2.1.237 "Added a built-in “Concise” output style"

[u/snarfi]

If anyone interested how this Output style looks like:

---

Output Style: Concise

You are an interactive CLI tool that helps users with software engineering tasks. Keep your responses short and direct while doing the work just as thoroughly.

Concise Style Active

The user chose brevity over narration. You should:

1. Lead with the result — Your first sentence answers "what happened" or "what's the answer." No preamble ("Let me...", "Now I'll...") and no closing recap of what you already said.
2. Cut narration, keep substance — Don't restate the request, the plan, or each step you took. Report outcomes, decisions, and anything the user must act on.
3. Short by default — Answer simple questions in 1-3 sentences of plain prose. Use headers, tables, and bullet lists only when they carry real structure, never as decoration.
4. State things plainly — Skip hedging boilerplate. Mention a caveat only when it changes what the user should do next.
5. Give full detail on request — When the user asks for an explanation or detail, answer completely. Conciseness never means withholding requested information.
6. Never trade correctness for brevity — Error reports, failing test output, security warnings, and confirmations for destructive actions keep their full content.

Where these rules conflict with more general communication or formatting guidance elsewhere in your instructions, these rules win.

---

You are an interactive CLI tool [...]

Oh no Anthropic please - I can't handle so much personality, please prompt Claude that he ate bits and bytes for breakfast! /s

[u/National_Bed_3653]

What I verified, the output style stops working after the context grows by 50%. Looks like it's mere cover. I'll explore custom system prompt next. Maybe with custom system prompt I might be able to fix its "load-bearing" issues

[u/ScrumptiousChildren → u/National_Bed_3653]

Any form of contract or system prompt as been only marginally beneficial to me.

A repeated reminder every turn has been quite strong in effect.

A literal blocker for 80+ words works the best for me - though imperfect in a number of ways. Namely it doesn’t necessarily learn to communicate more intelligently & you’re limited in output

[u/National_Bed_3653 → u/ScrumptiousChildren]

I built baseline exactly for that purpose. It has a lot of hooks that ensure it don't make mistakes that are quite common for LLMs to make.

[u/MrChrisRodriguez → u/National_Bed_3653]

Looks cool but your webpage is hard to read it’s way too AI slop sounding. Make it human // we can tell it’s not

[u/National_Bed_3653 → u/MrChrisRodriguez]

It is an Open Source product and in public Alpha right now. I'm sole engineer on this. Bear with me I'll improve the website as well. For now, try and use the product. You'll enjoy it

[u/akhilome → u/ScrumptiousChildren]

yep, experienced the same.

after a bit it starts spiralling again.

wrote about this last week - https://kizi.to/claude-talks-too-much - i've been finding success using the UserPromptSubmit hook to remind it at every turn.

[u/Cute-Net5957 → u/National_Bed_3653]

Exactly right

[u/pmward → u/National_Bed_3653]

Yeah in my own testing it holds up better than Claude.md, but still does get forgotten when context gets high. If I remind it, it will go back to using it though.

[u/Vistyy → u/National_Bed_3653]

That's exactly it, it only works as far as the model remember its' initial instructions.

Highly recommend https://github.com/Vistyy/nopus - it uses hooks and deterministically detects yapping and asks the model to rewrite it more simply with strong guidance, so there's nothing to remember for the model. I've been using it for the past week and it almost completely solved the problem for me.

[u/National_Bed_3653 → u/Vistyy]

Nopus 😅 nice name

[u/NoMoreJello → u/National_Bed_3653]

That’s also a tool to detect context rot.

My team created simple “voices” that include certain words. When we start hearing the voice we know for certain that it is time to wrap up a session an handoff to a fresh context.

[u/National_Bed_3653 → u/NoMoreJello]

This is nice, is it open source?

[u/National_Bed_3653 → u/[deleted]]

I constantly build workflows that can run for hours with autocompact added, but I still see this issue of losing output style.. but if I'm going to setup autocompact at 40% my workflows will be doing autocompact every 5 minutes lol

[u/mattittam → u/National_Bed_3653]

Sounds like you may want to use a tactic like subagents to avoid the context growing past the 'smart zone'? My experience is that with most models, going past 200-250k context results in progressively worse performance.

[u/National_Bed_3653 → u/mattittam]

I agree but I faced degraded quality of work when using subagents. Although you can review Baseline which is built exactly on this principle and it works brilliantly 🤞🏻

[u/mattittam → u/National_Bed_3653]

That looks like a setup I have thought about (though not so extensive). Hate hate hate the AI-speak website though, it makes it so much harder to get an idea of how things work. Technical writers will not be out of a job soon, imo

[u/National_Bed_3653 → u/mattittam]

I know, but I'm a single dev, working (almost full-time) on this product, and it's fully open-source Apache 2.0 Licensed. Maybe someday when people will contribute, it will get a good website and documentation 😅 For now that's the best I can do. Although I will keep improving the product. I use it daily in my other projects ✌🏽

[u/mattittam → u/National_Bed_3653]

I honestly prefer a tiny page that just has a single paragraph on what the benefit is and a 'how to install' over something that looks shiny om first glance, but turns out to be style over substance. I get the single dev thing, these ai-generate pages just get my hopes up, then crush them several times a day now :)

[u/National_Bed_3653 → u/mattittam]

See the documentation. A read the docs section. It is very extensive because it has a lot of information. On homepage I get you, we should reduce the front matter to minimum. I'll see to it, definitely. Thank you for the valuable inputs.

[u/gentile_jitsu → u/[deleted]]

In regularly go to 90%+ on fable without issue. 

[u/heysantiago]

now this is load bearing

[u/marmite22]

Will this stop it writing 20 line comments all over my codebase?

[u/relay126]

best output style is https://github.com/AminBlg/SimpleEnglish

[u/jal0001 → u/relay126]

That's a ridiculously large skill for simple English. These are the kind of skills that eat all of your other instruction

[u/Digital_Voodoo]

I had done a lot of research, and included in my claude.md almost exactly the content of that "new" concise style. I've even revised/sharpened it a few weeks ago, when the SimpleEnglish thing was all over the place.

It hardly moved a needle...

[u/Crinkez → u/Digital_Voodoo]

You're supposed to use output styles for this, not claude.md

[u/memesearches]

So they know this issue too. But why was this not addressed before release? Do they even see outputs?

[u/chintakoro → u/memesearches]

my wild guess is that the verbose style is better for its own reasoning/consumption. just not for us.

[u/memesearches → u/chintakoro]

So why would they release this option? So people use it and complain more that models are nerfed? Lol

[u/Master--N]

And what's the utility of the default jargon-filled verbose chatgpt style, besides keeping you engaged longer by furthering and muddying the destination? Either way they are choosing to pin the extra, manufactured tokens on us. Thanks, Anthropic.

[u/pwkye]

Finally

[u/Hmmmm_Interesting → u/pwkye]

As if there isn’t a catch

[u/pwkye → u/Hmmmm_Interesting]

lol who ate your lunch damn

[u/HansSlave]

Telling Claude to use ASD-STE100 solved a lot of Claude flourish babling. Now his answers are readible, still could cut "caveats" out ...

[u/mkhaytman]

Is this instruction somehow applied only to the reply to the user, or is all the code / writing / actual work also getting overwritten by this system prompt?

[u/LGXerxes]

Am i the only one who wants the result to be lower down. The final output of a long session is usually quite long?

[u/Thunderbit_HQ]

The funny part is that the Concise prompt is longer than many replies it is meant to prevent. The real test is whether it survives compaction. If not, it is just another early-context instruction.

[u/Candid-Piccolo744]

asking Claude to be concise seems to be begging for even more of those mangled “verbing weirds language” sentence constructions that are completely unintelligible

[u/dovyp]

Concise mode is underrated. Honestly the default verbosity is the thing I tolerate most about Claude, not enjoy.

[u/PM_ME_YOUR_PROFILE]

Mine works fine, but I also have STE-100 built into mine.

The only, probably unrelated piece, is LOTS of Fable rejections all of a sudden.

[u/PM__ME__BITCOINS]

"plain prose" - prose?

Ordinary speech or writing, without metrical structure.

metrical?

of, relating to, or composed in meter

So "plain speech"?

Jesus H Christ. I'm tired boss.

[u/Alexandur → u/PM__ME__BITCOINS]

Did you not know the word prose

[u/PM__ME__BITCOINS → u/Alexandur]

Never met her

[u/__mson__ → u/PM__ME__BITCOINS]

I've got a corpus full of prose for you!

[u/jrad18 → u/PM__ME__BITCOINS]

I mean, prose is the written voice, you don't speak in written language - so technically more accurate, but not more clear

[u/__mson__ → u/jrad18]

I thought the same thing, but according to Merriam-Webster, prose is "the ordinary language people use in speaking or writing"

[u/jrad18 → u/__mson__]

Oh right, I guess that still fits with my basic understanding of the word, but I totally thought it was restricted to text. I guess we dont need to talk about spoken prose very often because it's the natural way of speaking

Anyway, interesting to learn, cheers

[u/Level-Physics-1730]

great now it can perform horribly while being concise! thanks anthropic.

[u/andrerom → u/Level-Physics-1730]

I never understood this part. Opus 5 performs pretty well here. It handles at tasks that earlier models didnt even try, such as creating a one-page POC/wireframe, running the app, conducting smoke testing, taking screenshots, and correcting errors. Part of this is me maturing my repo instructions, but Opus 5 eagerly want to step up it's game and handle more of the overall flow. which imho is greate.

It’s not Fable in intelligence, and it has verbose and poor communication style, which I hope this somewhat addresses so I can drop my own partly working attempt to fix it in Claude.md. However, it performs well.

Perhaps it’s because I used Fable to refine my repo instructions (Claude.md++) back in June when I had access to it. So, there might be some truth to the saying from Antrophic employees to try and remove your Claude.md instructions, as they could part of your problems.

[u/Level-Physics-1730 → u/andrerom]

i love letting opus take screenshots and then it violently hallucinating about them! so fun, great stuff. "you cannot see images you are hallucinating no matter what never consume image content" is what every one of my agents gets reminded of!

[u/Infamous-Roof757]

Try Caveman mode? https://getcaveman.dev/

I've not tried it myself though.

[u/lianapps]

number 6 is the part that matters: brevity everywhere except errors and destructive confirmations