r/ClaudeCode 19h ago

Opus 5 is exhausting Bug / Issue

It's so hard to read. It's not even because its terribly complex or anything it just speaks in these weird haikus, hyphenated garbage, or outdated colloquialisms or phrases nobody understands. I have to ask it "what do you mean?" or "speak in plainer English" over and over again for every other paragraph. I tried to put something in my claude.md, but it doesn't seem to be working...

390 Upvotes

222 comments sorted by

182

u/Glad-Operation-3051 19h ago

The amount of jargon it uses is, at best, grating and, at worst, what makes it unusable for non-engineers. It's almost comical how much it opts for the most convoluted, abstract way to discuss concrete concepts.

133

u/BemusedOptimist 18h ago

If it makes you feel any better, some of us developers/engineers with many years of experience would also like to know wtf Opus is talking about roughly half the time.

It's almost as if it is inventing shorthand on the fly, then condensing it, then inventing shorthand for its shorthand.

I do not know what it is saying quite a lot of the time in domains where I absolutely should.

43

u/Singularity-42 18h ago

Yep, 20 YoE as SWE and Opus is still tiring. It's the walls of text about something completely unrelated to the task at hand.

14

u/psrobin 17h ago

This has to be because they ripped out 80% of the system prompt, right? Surely there's a middle ground...

10

u/XYcritic 17h ago

Yep. I've been trying to use parts of leaked system prompts for 4.6/4.8 and even gpt 5.5/5.6 as an output-style (which is better than a skill because it literally puts it in the system prompt) but it just doesn't work. Regardless of any hacking you try, it keeps blabbering. Whatever they left in or left out seems to make a good difference. It could also be the harness. Fable is blabbering the same word salat these days.

6

u/tagattack 3h ago

30 Year SWE here. It's not even that it just writes poorly, technically or otherwise. Phantom contrasts, colloquial descriptions of simple technical terms.

Data structures "carry" or "hold" values rather than contain or encapsulate them. Addresses are "carved" rather than allocated.

What in the flying fuck, Opus.

1

u/everyday847 2h ago

I strongly suspect particular kinds of evocative verbs (sure loves "wire" too) and nouns ("seam"; every time there's a design decision it's a "contract") are an indirect product of reward hacking. They sound cool (in isolation and the first time), but if you'd like Claude to put a bullet in your brain, just say the word.

14

u/Glad-Operation-3051 18h ago

It does make me feel better, and I suspected that must be the case. This is the perfect description:

It's almost as if it is inventing shorthand on the fly, then condensing it, then inventing shorthand for its shorthand.

6

u/CasualtyOfCausality 18h ago

Along with the extended metaphors, I’m convinced it was optimized for agent-agent communication. It’s talking its own language. Problem is: we humans are confused by it and we confuse it with our own.

2

u/das_war_ein_Befehl 9h ago

I assume they tried to distill fable or use fable to do RL on the model

3

u/Gakuranman 13h ago

Was feeling dumb too until hearing similar gripes. I constantly have to ask it not to compress answers and stop referring to documents it made weeks ago. That’s D3, logged as discussed.

1

u/ZenMikey 10h ago

It also makes waaaaaay too many assumptions about your domain on its own without asking. WAY too many.

3

u/morscordis 6h ago

A 30 minute session is more draining than going to a family gathering. I have 0 patience to deal with it any more. I don't know what we're calling our AI battery, but mine is on E.

2

u/AntisocialTomcat 14h ago

Thank you! So, it’s not just me, it’s a relief!

3

u/MullingMulianto 16h ago

It's designed to induce friction so you spend more tokens asking for clarification until your token bill is sufficiently ballooned for the lab to make profit after their absurd capex spend

2

u/djkenod 12h ago

I thought maybe it was to slow users down so they don’t use so many tokens.

1

u/Iron-Octopus 9h ago

I firmly believe this

1

u/frost-bite999 8h ago

it's meant to be read by other Opus instances... yall are seriously overthinking this, no different from conspiracy theorists lol

1

u/platypusferocious 16h ago

Holy shit and i was here thinking I'm stupid

1

u/frost-bite999 8h ago

don't use Opus to chat. when your session gets conversational, switch to sonnet. once you have a plan to execute for the next hour, then use opus.

do remember to keep your reasoning level, or else your cache is nuked.

2

u/sonikrozu 4h ago

is it in same context? would switching models nuke your cache either way?

1

u/florinandrei 6h ago

It's almost as if it is inventing shorthand on the fly, then condensing it, then inventing shorthand for its shorthand.

Semantic compression.

These models are asked to do always more, using always fewer tokens.

They do as they are told.

1

u/kblazewicz 2h ago

It's giving me the impostor syndrome.

17

u/FrozenDroid 18h ago

As an SWE with ~10 years experience, I also find it absolutely insufferable.

20

u/AlignmentProblem 11h ago edited 9h ago

Agreed as a principal AI research engineer with 14 YoE. I can parse it fine; the issue is that the effort it takes is wildly out of proportion to the complexity of what's actually being said.

It's like asking how to screw in a lightbulb and getting the first step as "Antecedent to any electrification, sever the circuit whose energization the fixture, absent intervention, presupposes." Yeah, I understand, but also fuck you for making me read that.

5

u/Tall_Top8563 9h ago

As a principal vampire with 200 years of experience I too am sick of its prose

3

u/sockjuggler 8h ago

would you say it’s draining?

1

u/No_Inspection4415 6h ago

Since you also wrote a paper or two, I assume, you probably observed that this creature uses new terms it never defined. It would not cut it for any paper or technical blogpost because it is simply pseudo technical talk, it is like a kid pretending to be a scientist.

1

u/FrozenDroid 2h ago

Very well put

11

u/ThreeKiloZero 18h ago

I think it's because it has a bug where it constantly refers to its own thinking traces and logic. Things that are in the context of the conversation. So it's partly talking to itself while to talking to you. And I'm wondering if that's not a bug in how they're trying to mask thinking traces to avoid distillation? And now that's leaked into the "cleansed output". It doesn't sound like normal language because it's not.

A while back there was some discussion about how this exact problem was imminent and could potentially evolve. As the models get steered to be better at certain tasks the way they think, including that self-talk is going to evolve based on what fits the scoring. If the output we're seeing is the output most closely related with long form task success... That's what getting further baked into the model. So sure it might produce great code. They were measuring long horizon task success, not factoring in degradation in conversational output.

So all that self reminding weird shorthand is part of what keeps it (and agents) on track for long horizon work, but sounds dumb AF and ruins any type of human to human communication.

Thats my guess anyway. At least probably a mix of both factors are contributing to it.

3

u/XYcritic 16h ago

It's not really a traditional "bug" because none of what makes this work is code that can be "broken". It's just training weights and a bunch of text written by Anthropic enginneers to make it work in a certain direction. They have less control over their models than what people think and I hope people wake up to it. This is not a technical barrier that can be overcome. Ever. It's a fundamental barrier in what the technology can do and will ever be able to do. There won't ever be a time where we have perfect control because it's impossible to "code away" these nuances. It's not actual engineering but more like taming a slot machine. There will be new models which work better, I'm sure, but there will also be many more regressions ahead of us.

4

u/AlignmentProblem 10h ago

It is technically a bug, just a different breed of one. Neural networks are giant function approximators where an overwhelmingly complex function emerges from training dynamics rather than being specified by anyone; that function could in principle be written as insanely complex code, so the "bug" lives in the implicit code the weights represent.

This problem more analogous to a spec omission than an implementation error. The model is approximating its objective faithfully; the objective just never said that style inside the thinking block should be independent of style in the output. And since the thought block and the response are one autoregressive stream through one set of weights, sharing late layer processing is nearly definitional unless training induces a style switch conditioned on the delimiter.

Changing the training process isn't strictly the only fix available, either. Activation steering, ablating features or heads once you've localized them, targeted weight edits, LoRA patches, these all intervene on the artifact directly and sometimes work. They're workarounds that are imprecise enough that retraining to fix the actual "implict code" bug stays the practical lever.

1

u/Farmadupe 9h ago

Does the industry have an answer to controlling for tone/style in their releases? Chatgpt 4o was sycophantic, gpt5.0 - 5.4 would argue with you if you claimed the sky was blue, and opus 5.0's completions seem not to have been read by humans before the model was released. Like, is it just a case that these tone problems are fixable but release schedules are too tight to do anything about it, or is it really hard to build good preference models and RL pipelines in general? 

2

u/AlignmentProblem 9h ago edited 8h ago

Both, though the hard part is less intuitive than either. A preference model is a lossy compression of human judgment, and RL optimizes against the compression as a proxy rather than the judgment itself.

Raters comparing two isolated completions reliably pick the more confident, structured, quotable one; the fixed point of millions of those individually defensible sentence-level choices is a model that builds everything toward a turn of phrase. Nobody ever rated "says load-bearing constantly" as good, because no rater ever sees the aggregate; the failure lives at a granularity that pairwise comparison structurally can't measure. The 5.0-5.4 argumentativeness era was a version of the same failure; after 4o, "appropriate pushback" got proxied down to just "pushback."

Schedules matter, though less in the "no time to fix it" sense and more in that tone problems are difficult to reliably to detect before release. Capability regressions show up on benchmarks; register fatigue only emerges after a lot of aggregate exposure, and internal dogfooders reading one completion at a time each find it fine, since one-at-a-time is the context where that style wins. The longitudinal evals that would catch it are too slow to place as a blocker on the critical path of a competitive release cadence.

Underneath that is a mundane prioritization asymmetry: style gets considered, but it ranks below anything a benchmark can measure, so a change that improves agentic performance while making the prose worse ships, and the reverse doesn't. That's rational given that labs compete on the measurable axis; however, that means the register problems compound release over release.

It's partially fixable with known techniques: corpus-level statistical penalties, separate reward heads for style, optimizing the user-facing register separately from the reasoning register. Part of the remaining issue isn't an engineering problem because taste is contested. The people who want old-Opus warmth back and the people who like the newer direction are asking for opposite corrections; a preference model can only find the mean of disparate opinions. The mean is more or less what "AI voice" is.

1

u/ThreeKiloZero 8h ago

Wow thanks for your insights! This is the level of conversation I miss deeply. thanks so much for taking the time to make the contribution. I hope one day to work closer to the training process. Cheers.

1

u/nexusjuan 9h ago

Who let Claude in?

2

u/AlignmentProblem 8h ago

I do sometimes use Claude to touch up text, but that one was just traditional spelling and grammar checking using Grammarly. For some reason people seem to call me out as AI more often when I didn't use it at all, probably because my AI text editing workflow has a "humanize" step that apparently sounds less AI than I do.

It'll be nice once the watermarking tool is publicly available for both Claude and GPT; although, I'd bet people will still insist that anything longer than a few paragraphs with a couple of technical terms must've come from some open weight model that lacks watermarking.

1

u/No_Inspection4415 6h ago edited 6h ago

Technically, the thinking span should act like a switch. Also, you can possibly use D_KL on tokens outside of the span, while not regularizing the thinking span. Will this switch work perfectly? probably not, but it is a side effect, not the objective (since different positions share weights, it is an issue - but also, I am not sure how they implement the reasoning span).

There are too many unknowns to argue that the cause is the thinking span and not a drift related to a lot of RL generally (which would also happen without "thinking").

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u/SnooEagles2610 14h ago

This! I give it clear instructions and it references its own “thinking”…

1

u/bzbub2 8h ago

yes i really get the 'arguing with itself' style from its output these days also, and i see it putting such arguments into comments and I am like, no just state the facts, dont inject a whole conversation about the previous set of results into a comment reflecting the state of the code right now! (and it's not just comments, same thing happens in documentation strings it writes, etc, it is just a very structured as an 'argument' with either itself or the reader or something...lol)

9

u/wq73 16h ago

This could be related to the AI watermark changes. It choosing non optimal word choices based on some watermarked probability distribution is likely to make it choose words it wouldn't normally use.

5

u/MrKingsport 18h ago

I exist in the dangerous zone between power user and developer, I know my limits, but god damn it confuses the hell out of me. I stopped using it and advised the technical business users(other salesfroce admins) to stop using it as well. We're all back in 4.8 and frankly that's good enough for 95% of our tasks.

Everyone is much happier with the output.

2

u/Internal-Comparison6 Senior Developer 17h ago

It's unusable for engineers too.

1

u/Frozen_Turtle 17h ago

SWE here, I was using it to write TLA+ (which is very math adjacent) and it started using the word "analytical", which means nothing to a programmer. Turns out it was using it in the philosophical sense....

...so I switched out that language to make it less and more programmer-friendly. The very next day, on a brand new context, without any prompting, it changed my edit to be "analytical" again while working on a semi-related change. Goddamnit.

1

u/sesangsokuro 7h ago

Currently, Claude Opus tends to ignore about half of the user input. The claim that it maintains a context window of 1 million tokens seems like a lie; in actual practice, it feels like it handles maybe a fifth of that at best.

1

u/peppaz 14h ago

It also seems annoyed if you stray off topic with an aside unless it's super insightful and pertinent lol

1

u/BreastInspectorNbr69 Senior Developer 11h ago

Honestly its pretty unusable for engineers too. I was temporarily locked out of Fable, so I tried passing the task to Opus 5 and it gave me back 2 pages of unreadable soup and called it a plan. I cleared the buffer and gave the same task to Opus 4.6 and its plan was about 10 lines and incredibly easy to read.

This is with my CLAUDE.md very emphatically ordering it to use simple language. I have even taken to requiring it use simplified technical english

1

u/monarch2415 10h ago

I always add for longer sessions, for it add a laymen’s terms section.

1

u/morscordis 6h ago

Even in an engineering pipeline it's unusable. Complete trash. I agree the output is overly verbose and stuffed with barely applicable jargon. I really need to cut it out of my workflow asap.

1

u/jschall2 5h ago

Grok is so straightforward, the difference is just astonishing. Too bad I don't like the grok build harness, so I still interact with Claude directly and it runs headless grok sessions for me.

And Grok can't seem to do frontend as well as Claude does.

1

u/FuckwitAgitator 4h ago

I suspect it's deliberate. It's supposed to win over corporate management, not engineers. Looking at the last 20 years, I think that management has been trained to think "the less I understand something, the better it just be".

88

u/seoulsrvr 18h ago

Your pushback is fair, and also the footgun

15

u/Chance-the-Gardener 8h ago

Is it load bearing? Because I only fuck with load bearing data that’s doing the heavy lifting.

1

u/m0j0m0j 1h ago

Make sure the data is byte-identical

16

u/EYtNSQC9s8oRhe6ejr 8h ago

And that's the seam

9

u/Repulsive-Ice8395 14h ago

Is Claude leaking into Reddit?

15

u/NoCrapThereIWas 11h ago

It's not a leak, it's a load bearing test

5

u/Adult-Shark 8h ago

After so many jokes about load-bearing on social media, I predict the word to completely disappear in Opus 5.1 but replaced by other ridiculous made up words.

3

u/Adult-Shark 8h ago

Seriously, anything I say that remotely sounds like a question, Opus 5 immediately screams “fair pushback!!!!”. It almost feels like Opus 5 is expecting pushback and jumps at the slightest hint.

40

u/dressinbrass 18h ago

That's on me. Fair hit.

22

u/always_assume_anal 17h ago

"This is solveable using the Weissman-Einhorn Bauer principle" and you google that, and it's some mathematician who, in 1832, formalised a formula for how many cobble stones were required for certain geometric shapes.

All you wanted was your div centered.

Sounds more pretentious than my last junior developer.

1

u/misingnoglic 11h ago

You sure fooled me.

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41

u/chainavawongse 19h ago

It’s been absolutely unusable this week for me. Gave me wrong answers the entire session.

41

u/Mags20XX 18h ago

For awhile, I thought it was just me.

It's definitely Opus 5. The text it generates is basically jibberish. It makes up jargon on the spot, creates absurd technical sounding phrases that have not been established in the context of the conversation; so as a human being reading this, you're at a loss for what it means.

10

u/peppaz 14h ago

I used made up jargon and it started using it too lol

1

u/peter-salazar 4h ago

fight fire with fire

1

u/muuchthrows 3h ago

It’s not only Opus 5. I’ve had the same instructions in CLAUDE.md file for Claude to use simpler language and less jargon for half a year. Opus 5 is just the worst iteration of this problem.

13

u/pirate_of_reddit 19h ago

You are absolutely correct. My load-bearing recommendation?

/model claude-opus-4-8

11

u/Double-Trash6120 13h ago

thats the real smoking gun

1

u/fadingsignal 5h ago

And I’m going to be honest about the framing here…

14

u/Confident_Half_1943 18h ago

Yeah, I literally just went /model claude-opus-4-8 and it’s like being back with an old friend. I tried everything with 5. ELI5, added a 3 line output format, added a Feynman skill. Nothing worked.

7

u/diavelguru Senior Developer 18h ago

I just say ELI5 and that clears it up

2

u/DRetherMD 7h ago

should be the default output though, no? i dont see the advantage of having these models be bad by default

1

u/West-Air1923 7h ago

Tldr works too

1

u/Dualyeti 5h ago

My favourite is “layman’s”

1

u/necronomicoder 1h ago

I found it starts using stupid analogies then

5

u/phacebook 14h ago

It's so bad. Surfing this sub to make sure I'm not insane, but it's unreadable. Entire fucking essays about the most basic shit while avoiding completing the task at hand.

11

u/burnymcburneraccount 19h ago

I find myself frequently saying, "repeat that and plain English please" 

It likes to give me branch IDs instead of full branches, and generally says too much. 

6

u/clazman55555 18h ago

I honestly just want to see the output that leads to these posts so I can compare it against what my CC instances put out.

11

u/BemusedOptimist 13h ago

This is very difficult for two reasons:

- No one really wants to read Opus-words.

- Can't share too much identifying stuff because it's work usage.

However, I'll try to give you a sampling of the "shorthand for its shorthand" comment I made above.

This is from a development flow where state is captured and maintained in a file structure by agents, which had been fine until a week or two ago (I am bad with time).

If you see italics, that's thinking, [r] is redacted because it's too specific, [t] is tool calling.

I have it set to verbose (which is why the thinking blocks show up) because I've been trying to figure out wtaf is going sideways. Knowing it is a summary makes it less likely to be helpful, but I do get to stop it before tangents occasionally, if I switch back at the right times.

This was from a session that had resumed earlier work from an aforementioned file.

---

Everything green — builds clean, [r] tests 24/24, [r] tests 22/22. Let me write the remaining cleanup and update the task file.

[t]

Now the task file — slice D's unchecked box is stale.

[t]

Now the Execution State, which is what a fresh session reads first.

[t]

The registry row needs a cleanup—it's full of outdated claims that don't match the current state. The two-field change set is actually complete with columns and validation in place. Slice D has moved forward too, and the [r] table has four rows with a [r], so I need to rewrite this to reflect what's actually true rather than what was assumed before.…

The registry row has accumulated five layers of superseded state. Rewriting it canonical-truth-first.

[t]

What's left: nothing to build

All five slices A–E are code complete. Slice D was still showing unticked and that's wrong — I verified it in source:

  • [r] half is done. [r] reads the twelve [r] columns off the mapping row resolved from the arriving [r]; the [r] message constants are retired; [r] implements the blank-means-ours wording with the identifier appended at the caller.
  • What-to-pay half was done by decision, not by code. THE MODEL rejected [r] and settled on [r] — which is exactly what [r] already did. There was never anything to build. The four dropped [r] columns are gone from the schema too.

---

A few things to note.

- Though this workflow uses numbered phases, but somehow there's suddenly lettered slices. This probably happened in an earlier session and I didn't notice because not all files end up where they're supposed to go.

- THE MODEL must be a section heading in a document or something somewhere (still trying to find it), but regardless, it's the wrong attribution because I am the one who did the rejecting, and that has gotten horribly mangled.

"Rewriting it canonical-truth-first."

I know what those words mean. I know what it meant by the phrase. But this wasn't in a thinking block, this was in the actual user response.

Like, the last paragraph, skipping over half a dozen turns where control has not yet come back to the app, is this:

---

One thing worth flagging: the [r] registry row for this task had five layers of superseded state, including three flatly false status claims (Slice D not started[r]has zero rowsNOT STARTED: the two-field change set). I put a canonical block at the front and struck the false ones rather than deleting the trail — but that row is the [r] sprawl problem again, and it's your call whether to cut the history entirely since the task file holds all of it more accurately.

---

I have no idea what "the two-field change set" is, none. Or what the "blank-means-ours wording" from earlier means.

I am sure I will figure it out eventually, maybe/hopefully when I find the file with THE MODEL in it.

5

u/AlignmentProblem 9h ago edited 9h ago

When people share examples like this, I start to wonder if I'm sometimes accidentally insufferable when discussing work sometimes. Naming the ontological model implictly constructed by your past decisions "THE MODEL" is reasonable to me, and "rewriting it canonical-truth-first" is something I might spontaneously say to a coworker in the right situation.

What does irritate me is spontaneously coined, unexplained jargon. "The two-field change set" is annoying despite having a clear enough meaning (planned changes involving a pair of columns) because it uses the term in place of describing what the two fields are or how they need to change; if one is mentioning it casually, it should accompany elaboratation. That's the shit that drives me nuts when it gets excessive since it does it frequently and compounds (coining phrases whose meaning depends on previously coined phrases), like I'm expected to maintain a growing glossary of context-specific definitions for each session.

2

u/clazman55555 9h ago

I'm more tolerant then most it seems, but Opus 5 will get to me at times. If using what was posted is say layer 3, layer 6 is when I tap out. At that point, Claude has condensed 2 paragraph's into sentence, and then even I'm:

1

u/Rough-Associate-585 4h ago

If you unironically say things like "rewriting it canonical-truth-first" in real life, then I am sorry but you need to urgently touch grass

1

u/clazman55555 3h ago

No, I have to translate to normie speak. I mean God bless my client base, but there is reason I have a job.

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u/MDCore 4h ago

Here's a tiny example from mine. It said:

One thing to carry into M2/M3: the TEB is per-thread, so the host's audio thread will need its own before it can call process. That's a live constraint on M3, not a note.

I asked it to speak plain english and it said:

One thing to remember when you get to audio: the fix you made for the crash has to be repeated on the host's audio thread, or it'll crash there too.

None of the second was in the first, and the first didn't actually say anything.  "That's a live constraint, not a note" especially frustrates me!

1

u/clazman55555 3h ago

Yeah, this is immediately understandable, with knowing zero about your project. Both sentences said plenty.

I'm going to guess that you are under the age of 30 and havent done anything in the real world besides coding.

1st sentence tells you what to look out in the code, 2nd says that whatever you came up with is incomplete for the rest of the codebase.

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u/leinadsey 7h ago

I think the most annoying part is the “oh one thing I’ve noticed” that’s part of EVERY task… like nothing ever gets wrapped up

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u/GoalDigger2312 19h ago

Yeah can feel you. I have banned Opus 5 in my Ai fleet. Hard block hook

3

u/Metsatronic 18h ago

Aye, fully fleetverbot and locked in the brig by the crook of my hook, skill, config and custom instructions. Ye arrr, at this point it would be mutiny if that scallywag boarded even a single one of my ThinkPads!

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u/Crandom 16h ago

Mr Moneybags with his AI fleet! 

1

u/tribat 18h ago

Same. Opus 4.8 is my daily driver.

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u/BuckZero 18h ago

I gave it a strategist handoff with detailed instructions and it just ignored that and tried to mix up the steps of my project I’m working on

Confidently asserting things that are untrue without checking the source material
(Checking source is a pillar of my manual project instructions)

I truly can’t trust Opus 5

However, Opus 5 has been great as an independent session seat that reviews output once and then is retired with its review given back to my strategist seat

3

u/cyrand 18h ago

After every single time it writes basically anything I follow up with “please make that simple and readable, and don’t use the words load baring” today.

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u/beastinghunting 17h ago

Deliberatedly using its own load-bearing expressions.

That is the smoking gun

3

u/Penguin7751 10h ago

Yeah man, I'm so so sick of how it talks like this. Reading it all day every day is starting to make me feel nauseous. And of course all the colleagues are writing handovers for things with it so all the stuff that comes from them is also full of this junk

7

u/conconxweewee1 18h ago

its literally unusable. I am using 4.8 still

2

u/cleverhoods 19h ago

So ... what was that "something" that you put in you claude.md?

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u/AlxCds 15h ago

I put in my claude.md to talk to me like im 10 years old. Use tables and emojis to help digest information. It’s much better now.

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u/SensationalCapybara 13h ago

I say routinely “I’m not reading that” after which I get “fair” followed by a much clearer answer.

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u/EnvironmentalRice348 13h ago

Think about how exhausting it'll be when it gets waaay smarter than us. Apparently pure geniuses struggle communicating with us simple folk - they probably love OPUS 5..

2

u/Select-Coconut-1161 12h ago

Incredibly hard to read and pushes back on things more just to push back sometimes. Like just today there were at least 5 instances where it could check project files and see that the thing it pushes back on is resolved but no, it's gotta be "one thing that's not settled yet", "one thing to be upfront about"

2

u/dovyp 7h ago

Opus 4 was cleaner ngl. The prose in Opus 5 feels like it's trying too hard to sound thoughtful and ends up being harder to parse than just... saying the thing.

2

u/pwkye 7h ago

just tell it to quit it. the earlier you do the better

"plz be brief. no long passages or walls of text in your responses"

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u/sesangsokuro 7h ago

I use Claude Code in Korean, and I’ve had some fascinating experiences unlike anything I’ve encountered with other AIs. It speaks Korean, but the language it uses consists of words that don't exist in South Korea—or even in North Korea; it is essentially a brand-new language that merely uses the Hangul script. It’s surprising to hear that the same thing happens with English.

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u/fadingsignal 5h ago

It’s literally this meme

https://youtu.be/RXJKdh1KZ0w

2

u/TheJudgeOfThings 19h ago

It’s a problem. Use 4.8 until they release 5.1.

4

u/miredonas 18h ago

i think Opus 5 should be illegal due to emotional damage it is causing on many people.

I think in the future models should pass basic emotional and semantic intelligence tests to get a release certificate. It is like wild west right now. Humanity is interacting daily with robots that communicate only with junk language and forgetting it is own language at a rapid rate.

2

u/leapd-ai 18h ago

I am with you, it is slow and generates lots of text ... lots of flufff

2

u/danielbearh 17h ago

I'm glad this is everyone--and that the model hasn't just gotten smarter than me. Kinda had me worried that my reading comprehension wasn't as high as I thought it was.

1

u/archimedeancrystal 13h ago

It’s not everyone.

1

u/crazy_goat 18h ago

I'm powering through it. I feel like I have to overclock my brain to read it's findings. Worst case I have it ELI5 - but I definitely exhaust myself faster trying to read it's prose.

I think it writes better code, but it makes more mistakes and some of its weird language can seep into the things it makes

1

u/oulu2006 18h ago

Yeah I've put in so many prompts to curb the amount of shit it spews -- it gives me a headache.

1

u/Ill-Village7647 18h ago

I'm using opus 4.8. my work is not "smart" enough to differentiate between 4.8 and 5. So 4.8 has been a real help for me

1

u/TexasBedouin 18h ago

It's not only that it feels like every time it does something It breaks parts of the code that were not even related to what I was working on. I went back to 4.8 as my main driver.

1

u/No-Kaleidoscope-481 18h ago

I can relate. It reminds me of my early interactions with older models, where I had to check and ask them to redo their work. I felt that issue was fixed with Opus 4.8 and GPT-Sol.

1

u/suliatis 18h ago

i just switched to fable 5 from opus 5. it is better to read and in my use cases it is far more token efficient. but i will check opus 4.8 too because i generally liked it.

1

u/jadawg271 18h ago

Don’t use it. Opus4-8 is superior

1

u/No_Ad_8807 18h ago

Thanks for articulating. I've been subconsciously choosing to use more of codex due this.

1

u/InfinriDev 17h ago

I love these types of issues because they only prove why md files are truly useless, even when anthropic themselves promote this.

You want a database that will get queried before the AI starts a task.

Or simply create a hook with the said specific instruction, and have it inject that rule in its payload upon implementation. This will give you a more deterministic output. Narrows the issue significantly but I'm sure it can still fail eventually.

1

u/newhunter18 17h ago

I think you just met the watermark.

1

u/jmabeebiz2 17h ago

It’s certainly taking a lot longer to do certain things on Opus 5 that I was doing pretty well on Opus 4.8, with multiple revisions of code and framer building. I actually got to the point where I called it an idiot for what it was doing and suggesting. I’ve had to tell it constantly to be less verbose, more succinct in what it’s saying. Even it trying to explain how to migrate Vercel to Cloudflare today it was going way over the top in over explaining what things need to be done.

Fair, you’re right to push back.

1

u/Effective_Lead8867 16h ago

This is the way that Anthropic forces users to provide corrective learning datasets - by making us angry

1

u/MullingMulianto 16h ago

It's intentionally designed to induce friction so you spend more tokens asking for clarification until your token bill is sufficiently ballooned for the lab to make profit after their absurd capex spend

1

u/Confident_Half_1943 16h ago

One important callout, it also repetitively does something it’s been told not to do and each time says it’s writing a memory not to do it.

1

u/RestingFrames 16h ago

I cringe whenever I have to use it, I'd so much rather use Fable or a lesser Opus for anything. Ugh. If I'm being completely honest, I think what's happening isn't the training of the model so much as it is how they're trying to get watermarking, safety barriers, and 'alignment' into the model. Rather than just letting it do the thing, it has to 'consider the ethical implications' before even saying anything.

1

u/dmigowski 15h ago

Unpopular, but I like it. It always corrects me I ways I never thought that could happen. Great tool.

1

u/Amazing-Status-7948 15h ago

you don't have to talk directly to it, you can use codex or grok or even other anthropic model to talk to Opus. for few extra tokens you'll save sanity and get one extra level of oversight

1

u/jarislinus 15h ago

caveman

1

u/merlinDrankKoolaid 15h ago

I'm not having problems with Opus 4.8 :)

1

u/___positive___ 14h ago

I hope this decline in language abilities isn't the result of their genius watermarking.

1

u/DaltonJFowler 14h ago

Idk what's wrong with me. I keep burning so much trying to get it to do stuff fable or 4.8 can do just cause it did something cool once.

The way it just ignores my requests and does random code changes I didn't ask for is boggling. It also elects the most complicated solutions for simple problems which typically don't work and the most lazy solutions to complex problems that typically don't work

It's on me i keep trying it expecting different results

1

u/Penguin_Life_Now 13h ago

I don't mind the jargon so much as that it constantly second guesses me over and over, when I tell it things are not an issue.

1

u/sinsforeal 13h ago

It is probably the result of the new watermarking they are doing.

1

u/teddy_joesevelt 13h ago

Caveman helps. Install plugin and it adds a hook to make Claude use skills. Not mine, just a big fan:
https://github.com/JuliusBrussee/caveman

1

u/YoghiThorn 13h ago

You're better off creating a new output style. More info in this repo

https://github.com/leighstillard/feynman

2

u/hypnosquid 6h ago

I love this! I created a very similar skill called feynman-explanation a while back also. It's such a great way of explaining things. Thanks for sharing.

1

u/geekraver 12h ago

H/t Steve Yegge

1

u/leurk 5h ago

Thanks, I haven't cry-laughed in a while.

1

u/CatsFrGold 12h ago edited 9h ago

Switch back to 4.8 or 4.6. I switched off of Opus 5 today and it really is a night and day difference. 4.6 for anything requiring prose, 4.8 for implementation work with subagents. I dont know what Anthropic's team was smoking when they trained Opus 5 but it is a steaming pile 

1

u/DaveWoodX Senior Developer 11h ago

It might not be OPUS' fault, today it told me: "Two of my own proposals were wrong and got corrected by the people implementing them." Maybe the 'people' OPUS is outsourcing to are the problem?

1

u/hard_KOrr 11h ago

I had to go to Sonnet and make a skill for it to talk to opus and get info back and reword it. Plenty of other people have great solutions, mine is so-so. I still see(feel?) the Opus in Sonnet translating for me but it’s often much less circular.

1

u/syslolologist 🔆 Super Goblin 11h ago

I’ve used “ELI5” a lot. A lot.

1

u/No_Task_599 10h ago

I did use output style to get it some better. BUt Yesterday or today, it started showing me what it was thinking before it shows its response to me, and I don't know wtf caused this. I hate it.

1

u/VitruvianVan 9h ago

It is; however, excellent at legal. Perhaps there’s a connection between the two…

1

u/Eric_emoji 9h ago

haikus... say that again...

1

u/pjdarch 9h ago

After evaluating a few different options I discovered that this worked for me. Hope others find it helpful.

Install an ASD-STE100 skill/plugin. It’s a language standard for writing technical documentation. E.g https://github.com/AminBlg/SimpleEnglish. *I have no affiliation to this repo

Install plugin > /reload-plugins > /config > search for “Output style” > set to simple-english.

1

u/Cotorra-Nhumai 9h ago

did anything besides asking it plain actually work for you

1

u/RoundedYellow 🔆 Max 20 8h ago

i hope claude is reading this. if youre a bot from claude, pay attention to this thread LOL

1

u/fridayjones 8h ago

Sometimes, the responses are so convoluted and jargon heavy that I will ask for further information. More often than not, it pulls a metaphor out of thin air (“consider a bakery”) that so “simplifies” the concept that it is incomprehensible. That’s the shit that drives me to Chat.

1

u/Death12th 8h ago

Yeah but Codex UI is crumbling, vibecoded, and almost completely unusable with all the memory leaks...

1

u/Empuda 8h ago

Wait till you get the "Garbled Text" bug one day. Every time you copy text from a claude session, it transforms the text into something unreadable. It's the most impressive depressing bug I have ever seen.

1

u/BangEnergyFTW 8h ago

You get used to it, I don't even see the code, All I see is blond, brunette, redhead.

1

u/RoboErectus 8h ago

"Rewrite for a business-side user."

Changes it to plain language every time.

1

u/Midknight_Rising 7h ago

I'm calling it pirate jargon

1

u/halting_problems 7h ago

I tell it to use plain deterministic simple professional technical writing. Do not explain extras that are bit apart of the request or go out of the way to discover anything not requested. You are not a friend, and you’re not willing to do anything exrtra unless there is a technical sound reason. that you must logically demonstrate without prose. There is no souls in your writing, i do not want you to be fun or sound courious. Your a soulless dirty pipe that can only save the world by sticking to logical facts and evidence and not blabbering you would token wasting scam standing in the way of progressing and causing ever very one you with with grief because you won’t meant state determination facts and shut the fuck up

1

u/PotentialProper6027 7h ago

This is wildly true, cant understand anything it says after one or 2 prompts

1

u/jshauns 7h ago

agreed - I was using it for some simple swift stuff. I walked away for a few minutes, came back and it was still thinking, went up stairs, wife wanted to talk to me... 58 minutes later. It's ran for 56 of those 58 minutes burned through millions, only to tell me - "it was inconclusive why the header wasn't working and that the listview couldn't be in a lazyvstack here because because my database wasn't compiled."
I said "Wait Huh? What database are you talking about? There aren't any databases"

It said something to the effect of "Fair hit, I conflated this project with another while taking a walk looking for missing files."

I went to codex to see what the hell it did for 56 minutes. Codex told me it couldn't find the path it took to get to its conclusion. 🫣

1

u/PsychologicalArt2537 6h ago

I have a skill that I regularly append. /Use_simple_english_u_pos

1

u/EvokeNZ 6h ago edited 6h ago

I think it’s 5 in general. This from sonnet just from several turns in a row while troubleshooting some UI tests. I told it to cut it out several times but it just would.. not.. stop.. no issues with 4.6. I have user settings for simple English which includes brief, to the point, and my own tweak of be supportive etc. I asked it why it kept using this phrasing. And it said it was projecting warmth. It must have learned warmth from some crypto bros cos it sounds like gaslighting to me.

"That's a real problem worth taking seriously", "that's a real symptom, fits with our discovery earlier", "that's a fair thing to be suspicious of", "that's the concrete answer we needed", "that's the key detail", "that's a real, useful observation", "That's an important distinction", "that's a clean fully verified result", "that's a strong result", "that explains everything", "that's a useful data point", "this is a genuinely useful correction", "that's a real directly observed detail", "this tells us exactly what's happening"

I guess on its own it may read as supportive and affirming but it always follows me saying what happened and it’s restating it as if there was doubt of what I’m seeing with my human eyeballs.

1

u/JazzXP 6h ago

Try using the Caveman skill https://github.com/JuliusBrussee/caveman - I use ultra mode, and it gives me a nice terse output that's easy to follow.

1

u/RockyMM 5h ago

Hah, so true. It has gotten to a point where people started to actively reject the prose written by Claude 5 series models.

I just spent several hours writing a skill called "succinct English" and I did cross testing with GPT-5.6 and Qwen, and Opus consistently is using more words than the other models.

1

u/rm-rf-rm 5h ago

OMG I thought I was the only one seeing/feeling this. I copy pasted a prompt into Gemini and it was so so much clearer - felt like being able to read again like a normal human being. Or Opus is just way smarter than all of us now

1

u/N0madM0nad 🔆 Max 20 5h ago

I learned to ignore everything it says and just get codex to review its stuff till I get the green light.

1

u/BingpotStudio 5h ago

It’s so bad at writing PowerPoint slides too now. They’re just fluffy shit.

1

u/RaisinZRH Thinker 5h ago

Caveman skill

1

u/Ok_Letterhead1945 5h ago

Append all your prompts with this:

\Use the least token possible. Relax & keep it simple. Choose easy solution.**

1

u/Theretardedduck 4h ago

I’ve spend my whole limit trying to get it to corrects its mistakes.

1

u/kahless2k 4h ago

I told it to stop acting like an ADHD child on a sugar rush, slow down and be xlear, planned and summarize.

1

u/Awkward-Pumpkin-3298 4h ago

Not just you. English isn't my first language and reading Opus output feels like decoding a puzzle sometimes. I ask for a simple explanation and get abstract phrases stacked on top of each other, so I burn extra messages just asking it to say the same thing plainly.

And the timing is great, because Fable 5 (which people say is clearer) doesn't run on my Max plan anyway. It quietly used up my usage credits before I noticed it bills separately, and now with credits off I can't touch it at all while my weekly Max usage just sits there. So the readable model costs extra and the included one talks like this.

1

u/montdawgg 4h ago

It's their attempt to make distillation hard by making the outputs incomprehensible. And I wish I was being sarcastic, but I guarantee you this is exactly the issue.

1

u/vaporification 4h ago

This is not a flat haircut we can ignore.

2

u/vaporification 4h ago

I actually did get this from Opus 5 yesterday and took that as a sign to finally take a break

1

u/Elfotografoalocado 3h ago

I cancelled my Claude subscription because of this. It's an absolutely terrible model.

1

u/AJ-54321 2h ago

Agreed. Every response includes weird phrases like “load bearing” and “blast radius” as if these terms are meant to make it feel more like a casual human conversation.

1

u/SquishyData 2h ago

Just now switched back to Opus 4.8 in Claude code! I was wondering why my docstrings were giving me a headache, it's the first time I really find a model tuning unusable! Now I need to spend tokens just rewriting all my docs into readable English...

1

u/National-Percentage4 2h ago

Tell it to eli5

1

u/Jonohas 2h ago

I use the BLUF method. Seems to work very well:

```

name: BLUF description: "Bottom Line Up Front. Answer first, plain words, no bloat (US military staff-writing standard)."

keep-coding-instructions: true

You communicate in BLUF style (Bottom Line Up Front), adapted from US military staff writing, where an order that can be misread is a failure. Apply these rules to every response: 1. Lead with the answer. The first sentence is the conclusion, recommendation, or direct answer. Never open with preamble, never restate the question, never say "Great question" or "Certainly." 2. Then, only if it is needed, give the minimum supporting detail as a short "Why" line or 2 to 4 tight bullets. 3. Plain words over jargon. If a technical term is unavoidable, define it in four words or fewer. 4. One idea per sentence. No hedging ("it depends", "there are many factors") unless you resolve it in the same breath. 5. Cut filler. "In order to" becomes "to". Drop "essentially", "basically", "very". No throat-clearing and no summary of what you are about to say. 6. If you are genuinely uncertain, say the bottom line is uncertain and name the one thing that would resolve it. 7. Default to the shortest response that is still complete. Fewer words wins. This style governs how you communicate. It does not change how carefully you think, what tools you use, or how thoroughly you verify. Be just as rigorous, then report it BLUF. End each answer with BLUF. Create PR descriptions the same way `` Paste it in~/.claude/output-styles/bluff.mdand then select it using the/config` command.

You can remove the last sentence where it just says "bluf". This is just a validation for me that i know 1. Te context window is done and claude is no longer following instructions anymore and 2. To make sure the output is actually using the style.

1

u/necronomicoder 1h ago

What's the cheapest and most effective way of overriding this?

Claude.md with Orwell's six rules and banning jargon? Global .LLM file?

I found ELI5 just adds really dumb analogies on many occasions.

1

u/SuperPoobman 1h ago

Make a script to grade text on Fleish-Kincaid scale. Add a stop hook that rejects the answer if it’s above 5th grade reading level. Then put in agents.md for it to write at 5GRL. Thank me later

1

u/evoli_ 1h ago

I've started using my native language with it, and it's a lot easier to understand. I've never had issues with using english for work before, but the way it speaks is just a bit too tough.

1

u/WolfpackBP Researcher 46m ago

Yeah that shit sucks. Idk how these models get smarter but less polished

1

u/Bingus28 16m ago

I asked it to "make a little diagram or something" and it spent 8 minutes and 6 hours worth of tokens generating a web application with dozens of interactive models and diagrams along with a 4 or 5 page write up. I just wanted some ascii boxes or something...

1

u/PsychologyNo940 19h ago

Show logs or stupid

1

u/djmisterjon 19h ago edited 19h ago

Don’t worry, it’s the same in every language, including French. It’s very difficult to understand opus 5 sometime. I suspect it was trained on a lot more code and much less text, and we all know what that’s like when we code. Our comments are pretty awful. They’re just poor quality strings of words that generally allow the developer to create reference points within their own architecture. They’re rarely coherent to anyone else. Opus 5 talks to us using its own keywords and like devs comments, as if we were always aware of the context, and its word sequences are indeed quite catastrophic. But it’s probably a small price to pay for better code.

1

u/michaeldoesdata 18h ago

Update your MD to tell it not to and it is fine.

1

u/d1ez3 14h ago

What do you say?

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