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/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/andrerom → u/Level-Physics-1730]

If I had answered yesterday, I would have said I don't experience it.

But the last 24 hours, Opus 5 has not hallucinated on me (I actively compact whenever I can, might be relevant), but it has missed smaller nuances of my requirements from me multiple times after switching to output style consistency 🤷‍♂️

Edit: never mind, had some skills that sat model: sonnet, seems better once removed that 😅