- > Claude often ignores CLAUDE.md
> The more information you have in the file that's not universally applicable to the tasks you have it working on, the more likely it is that Claude will ignore your instructions in the file
Claude.md files can get pretty long, and many times Claude Code just stops following a lot of the directions specified in the file
A friend of mine tells Claude to always address him as “Mr Tinkleberry”, he says he can tell Claude is not paying attention to the instructions on Claude.md, when Claude stops calling him “Mr Tinkleberry” consistently
- From the article:
> We recommend keeping task-specific instructions in separate markdown files with self-descriptive names somewhere in your project. Then, in your CLAUDE.md file, you can include a list of these files with a brief description of each, and instruct Claude to decide which (if any) are relevant and to read them before it starts working.
I've been doing this since the early days of agentic coding though I've always personally referred to it as the Table-of-Contents approach to keep the context window relatively streamlined. Here's a snippet of my CLAUDE.md file that demonstrates this approach:
# Documentation References
- When adding CSS, refer to: docs/ADDING_CSS.md
- When adding assets, refer to: docs/ADDING_ASSETS.md
- When working with user data, refer to: docs/STORAGE_MANAGER.md
Full CLAUDE.md file for reference:https://gist.github.com/scpedicini/179626cfb022452bb39eff10b...
by johnsmith1840
9 subcomments
- I don't get the point. Point it at your relevent files ask it to review discuss the update refine it's understanding and then tell it to go.
I have found that more context comments and info damage quality on hard problems.
I actually for a long time now have two views for my code.
1. The raw code with no empty space or comments.
2. Code with comments
I never give the second to my LLM. The more context you give the lower it's upper end of quality becomes. This is just a habit I've picked up using LLMs every day hours a day since gpt3.5 it allows me to reach farther into extreme complexity.
I suppose I don't know what most people are using LLMs for but the higher complexity your work entails the less noise you should inject into it. It's tempting to add massive amounts of xontext but I've routinely found that fails on the higher levels of coding complexity and uniqueness. It was more apparent in earlier models newer ones will handle tons of context you just won't be able to get those upper ends of quality.
Compute to informatio ratio is all that matters. Compute is capped.
- There is far much easier way to do this and one that is perfectly aligned with how these tools work.
It is called documenting your code!
Just write what this file is supposed to do in a clear concise way. It acts as a prompt, it provides much needed context specific to the file and it is used only when necessary.
Another tip is to add README.md files where possible and where it helps. What is this folder for? Nobody knows! Write a README.md file. It is not a rocket science.
What people often forget about LLMs is that they are largely trained on public information which means that nothing new needs to be invented.
You don't have to "prompt it just the right way".
What you have to do is to use the same old good best practices.
by gonzalohm
6 subcomments
- Probably a lot of people here disagree with this feeling. But my take is that if setting up all the AI infrastructure and onboarding to my code is going to take this amount of effort, then I might as well code the damn thing myself which is what I'm getting paid to (and enjoy doing anyway)
by serial_dev
4 subcomments
- I’m sure I’m just working like a caveman, but I simply highlight the relevant code, add it to the chat, and talk to these tools as if they were my colleagues and I’m getting pretty good results.
About 12 to 6 months ago this was not the case (with or without .md files), I was getting mainly subpar result, so I’m assuming that the models have improved a lot.
Basically, I found that they not make that much of a difference, the model is either good enough or not…
I know (or at least I suppose) that these markdown files could bring some marginal improvements, but at this point, I don’t really care.
I assume this is an unpopular take because I see so many people treat these files as if they were black magic or silver bullet that 100x their already 1000x productivity.
- Writing and updating CLAUDE.md or AGENTS.md feels like pointless to me. Humans are the real audience for documentation. The code changes too fast, and LLMs are stateless anyway.
What’s been working is just letting the LLM explore the relevant part of the code to acquire the context, defining the problem or feature, and asking for a couple of ways to tackle it. All in a one short prompt.
That usually gets me solid options to pick and build it out.
And always do, one session for one problem.
This is my lazy approach to getting useful help from an LLM.
- > we recommend keeping task-specific instructions in separate markdown files with self-descriptive names somewhere in your project.
Why should we do this when anthropic specifically recommends creating multiple CLAUDE.md files in various directories where the information is specific and pertinent? It seems to me that anthropic has designed claude to look for claude.md for guidance, and randomly named markdown files may or may not stand out to it as it searches the directory.
You can place CLAUDE.md files in several locations:
> The root of your repo, or wherever you run claude from (the most common usage). Name it CLAUDE.md and check it into git so that you can share it across sessions and with your team (recommended), or name it CLAUDE.local.md and .gitignore it
Any parent of the directory where you run claude. This is most useful for monorepos, where you might run claude from root/foo, and have CLAUDE.md files in both root/CLAUDE.md and root/foo/CLAUDE.md. Both of these will be pulled into context automatically
Any child of the directory where you run claude. This is the inverse of the above, and in this case, Claude will pull in CLAUDE.md files on demand when you work with files in child directories
Your home folder (~/.claude/CLAUDE.md), which applies it to all your claude sessions
https://www.anthropic.com/engineering/claude-code-best-pract...
- I have found enabling the codebase itself to be the “Claude.md” to be most effective. In other words, set up effective automated checks for linting, type checking, unit tests etc and tell Claude to always run these before completing a task. If the agent keeps doing something you don’t like, then a linting update or an additional test often is more effective than trying to tinker with the Claude.md file. Also, ensure docs on the codebase are up to date and tell Claude to read relevant parts when working on a task and of course update the docs for each new task. YMMV but this has worked for me.
- Here's an idea for LLM makers: allow for a very rigid and structured Claude.md file. One that gives detailed instructions, as void of ambiguity as possible. Then go and refine said language, allow maybe for more than one file to give it some file structure. Iterate on that for a few years and if you ever need a name for it, you might wanna give it a name describing something that describes a program, or maybe if you are inclined enough....a programming language.
Have we really reached the low point that we need tutorials on how to coerce a LLM into doing what we want instead of just....writing the god damn code?
- I've gotten quite a bit of utility out of my current setup[0]:
Some explicit things I found helpful: Have the agent address you as something specific! This way you know if the agent is paying attention to your detailed instructions.
Rationality, as in the stuff practiced on early Less Wrong, gives a great language for constraining the agent, and since it's read The Sequences and everything else you can include pointers and the more you do the more it will nudge it into that mode of thought.
The explicit "This is what I'm doing, this is what I expect" pattern has been hugely useful for both me monitoring it/coming back to see what it did, and it itself. It makes it more likely to recover when it goes down a bad path.
The system reminder this article mentions is definitely there but I have not noticed it messing much with adherence. I wish there were some sort of power user mode to turn it off though!
Also, this is probably too long! But I have been experimenting and iterating for a while, and this is what is working best currently. Not that I've been able to hold any other part constant -- Opus 4.5 really is remarkable.
[0]: https://gist.github.com/ctoth/d8e629209ff1d9748185b9830fa4e7...
by saberience
0 subcomment
- I find the Claude.md file mostly useless. It seems to be 50/50 or LESS that Claude.md even reads/uses this file.
You can easily test this by adding some mandatory instruction into the file. E.g. "Any new method you write must have less than 50 lines or code." Then use Claude for ten minutes and watch it blow through this limit again and again.
I use CC and Codex extensively and I constantly am resetting my context and manually pasting my custom instructions in again and again, because these models DO NOT remember or pay attention to Claude.md or Agents.md etc.
- > we recommend keeping task-specific instructions in separate markdown files with self-descriptive names somewhere in your project.
Should do this for human developers too. Can't count the number of times I've been thrown onto a project and had to spend a significant amount of time opening and skimming files just to answer simple questions that should be answered in high-level docs like this.
- I have Claude itself write CLAUDE.md. Once it is informed of its context (e.g., "README.md is for users, CLAUDE.md is for you") you can say things like, "update readme and claudemd" and it will do it. I find this especially useful for prompts like, "update claudemd to make absolutely certain that you check the API docs every single time before making assumptions about its behavior" — I don't need to know what magick spell will make that happen, just that it does happen.
- >Frontier thinking LLMs can follow ~ 150-200 instructions with reasonable consistency.
Doesn't that mean that Claude Code's system prompt exhausts that budget before you even get to CLAUDE.md and the user prompt?
Edit: They say Claude Code's system prompt has 50. I might have misjudged then. It seemed pretty verbose to me!
The part about smaller models attending to fewer instructions is interesting too, since most of what was added doesn't seem necessary for the big models. I thought they added them so Haiku could handle the job as well, despite a relative lack of common sense.
by candiddevmike
1 subcomments
- None of this should be necessary if these tools did what they say on the tin, and most of this advice will probably age like milk.
Write readmes for humans, not LLMs. That's where the ball is going.
- That paper the article references is old at this point. No GPT 5.1, no Gemini 3, which both were game changers. I'd love to see their instruction following graphs.
- I think this is an overall good approach and I've got allright results with a similar approach - I still think that this CLAUDE.md experience is too magical and that Anthropic should really focus on it.
Actually having official guidelines in their docs would be a good entrypoint, even though I guess we have this which is the closest available from anything official for now: https://www.claude.com/blog/using-claude-md-files
One interesting thing I also noticed and used recently is that Claude Code ships with a @agent-claude-code-guide. I've used it to review and update my dev workflow / CLAUDE.md file but I've got mixed feelings on the discussion with the subagent.
- That's a good write up. Very useful to know. I'm sort of on the outside of all this. I've only sort of dabbled and now use copilot quite a lot with claude. What's being said here, reminds me a lot of CPU registers. If you think about the limited space in CPU registers and the processing of information is astounding, how much we're actually able to do. So we actually need higher layers of systems and operating systems to help manage all of this. So it feels like a lot of what's being said. Here will end up inevitably being an automated system or compiler or effectively an operating system. Even something basic like a paging system would make a lot of difference.
- I'm not sure if Claude Code has integrated it in its system prompts or not since it's moving at breakneck speed, but one instruction I like putting on all of my projects is to "Prompt for technical decisions from user when choices are unsure". This would almost always trigger the prompting feature that Claude Code has for me when it's got some uncertainty about the instructions I gave it, giving me options or alternatives on how to approach the problem when planning or executing.
This way, it's got more of a chance in generating something that I wanted, rather than running off on it's own.
by prettyblocks
1 subcomments
- The advice here seems to assume a single .md file with instructions for the whole project, but the AGENTS.md methodology as supported by agents like github copilot is to break out more specific AGENTS.md files in the subdirectories in your code base. I wonder how and if the tips shared change assuming a flow with a bunch of focused AGENTS.md files throughout the code.
by jasonjmcghee
1 subcomments
- Interesting selection of models for the "instruction count vs. accuracy" plot. Curious when that was done and why they chose those models. How well does ChatGPT 5/5.1 (and codex/mini/nano variants), Gemini 3, Claude Haiku/Sonnet/Opus 4.5, recent grok models, Kimi 2 Thinking etc (this generation of models) do?
by eric-burel
3 subcomments
- "You can investigate this yourself by putting a logging proxy between the claude code CLI and the Anthropic API using ANTHROPIC_BASE_URL" I'd be eager to read a tutorial about that I never know which tool to favour for doing that when you're not a system or network expert.
- I've recently started using a similar approach for my own projects. providing a high-level architecture overview in a single markdown file really helps the LLM understand the 'why' behind the code, not just the 'how'.
Does anyone have a specific structure or template for Claude.md that works best for frontend-heavy projects (like React/Vite)? I find that's where the context window often gets cluttered.
- I already forgot CLAUDE.md, I generate and update it by AI, I prefer to keep design, tasks, docs folder instead. It is always better to ask it to read a
some spec docs and read the real code first before doing anything.
- I always read these articles and always fail to find a good example of CLAUDE.md
Why not just to show one?
- Ah, never knew about this injection…
<system-reminder>
IMPORTANT: this context may or may not be relevant to your tasks.
You should not respond to this context unless it is highly relevant to your task.
</system-reminder>
Perhaps a small proxy between Claude code and the API to enforce following CLAUDE.md may improve things… I may try this
- It seems overall a good set of guidelines. I appreciate some of the observations being backed up by data.
What I find most interesting is how a hierarchical / recursive context construct begins to emerge. The authors' note of "root" claude.md as well as the opening comments on LLMs being stateless ring to me like a bell. I think soon we will start seeing stateful LLMs, via clever manipulation of scope and context. Something akin to memory, as we humans perceive it.
by philipp-gayret
0 subcomment
- I find writing a good CLAUDE.md is done by running /init, and having the LLM write it. If you need more controls on how it should work, I would highly recommend you implement it in an unavoidable way via hooks and not in a handwritten note to your LLM.
- Here is my take, on writing a good claude.md.
I had very good results with my 3 file approach. And it has also been inspired by the great blog posts that Human Layer is publishing from time to time
https://github.com/marcuspuchalla/claude-project-management
- PSA: Claude can also use .github/copilot-instructions.md
If you're using VSCode, that is automatically added to context (and I think in Zed that happens as well, although I can't verify right now).
- Oh yeah I added a CLAUDE.md to my project the other day: https://github.com/grishka/Smithereen/blob/master/CLAUDE.md
Is it a good one?
by VimEscapeArtist
1 subcomments
- What's the actual completion rate for Advent of Code? I'd bet the majority of participants drop off before day 25, even among those aiming to complete it.
Is this intentional? Is AoC designed as an elite challenge, or is the journey more important than finishing?
- I think this could work really well for infrastructure/ops style work where the LLM will not be able to grasp the full context of say the network from just a few files that you have open.
But as others are saying this is just basic documentation that should be done anyway.
- A good Claude.md only needs one line:
Read your instructions from Agents.md
- I copied this post and gave it to claude code, and had it self-modify CLAUDE.md. It.. worked really well.
by Ozzie_osman
2 subcomments
- Has anyone had success getting Claude to write it's own Claude.md file? It should be able to deduce rules by looking at the code, documentation, and PR comments.
by rootusrootus
0 subcomment
- Ha, I just tell Claude to write it. My results have been generally fine, but I only use Claude on a simple codebase that is well documented already. Maybe I will hand-edit it to see if I can see any improvements.
- > Claude code injects the following system reminder…
OMG this finally makes sense.
Is there any way to turn off this behavior?
Or better yet is there a way to filter the context that is being sent?
- I have been using Claude.md to stuff way too many instructions so this article was an eye opener. Btw, any tips for Claude.md when one uses subagents?
- I was waiting for someone to build this so that I can chuck it into CLAUDE and tell it how to write good MD.
- > Regardless of which model you're using, you may notice that Claude frequently ignores your CLAUDE.md file's contents.
This is a news for me. And at the same time it isn’t. Without the knowledge of how the models actually work, most of the prompting is guesstimate at best. You have no control over models via prompts.
- I was expecting the traditional AI-written slop about AI, but this is actually really good. In particular, the "As instruction count increases, instruction-following quality decreases uniformly" section and associated graph is truly fantastic! To my mind, the ability to follow long lists of rules is one of the most obvious ways that virtually all AI models fail today. That's why I think that graph is so useful -- I've never seen someone go and systematically measure it before!
I would love to see it extended to show Codex, which to my mind is by far the best at rule-following. (I'd also be curious to see how Gemini 3 performs.)
by bryanhogan
0 subcomment
- I've been very satisfied with creating a short AGENTS.md file with the project basics, and then also including references to where to find more information / context, like a /context folder that has markdown files such as app-description.md.
- Honestly I’d rather google get their gemini tool in better shape. I know for a fact it doesn’t ignore instructions like Claude code does but it is horrible at editing files.
- Looking for a similar GEMINI.md
by boredtofears
0 subcomment
- It would be nice to see an actual example of what a good claude.md that implements all of these recommendations looks like.
- I pointed CC to this URL and told it to fix my files in planning mode. It gave me some options and did all of the work.
by foobarbecue
1 subcomments
- Funny how this is exactly the documentation you'd need to make it easy for a human to work with the codebase. Perhaps this'll be the greatest thing about LLMs -- they force people to write developer guides for their code. Of course, people are going to ask an LLM to write the CLAUDE.md and then it'll just be more slop...
- "Here's how to use the slop machine better" is such a ridiculous pretense for a blog or article. You simply write a sentence and it approximates it. That is hardly worth any literature being written as it is so self obvious.
- I've been a customer since sonnet 3.5. It is coming to the point where opus 4.5 usually does better than whatever your instructions say on claude.md just by reading your code and having a general sense of what your preferences are.
I used to instruct about coding style (prefer functions, avoid classes, use structs for complex params and returns, avoid member functions unless needed by shared state, avoid superfluous comments, avoid silly utf8 glyphs, AoS vs SoA, dry, etc)
I removed all my instructions and it basically never violates those points.
by max-privatevoid
1 subcomments
- The only good Claude.md is a deleted Claude.md.
by brcmthrowaway
1 subcomments
- Is CLAUDE.md required when claude has a --continue option?
by AndyNemmity
0 subcomment
- it's always funny, i think the opposite. I use a massive CLAUDE.md file, but it's targetted towards very specific details of what to do, and what not to do.
I have a full system of agents, hooks, skills, and commands, and it all works for me quite well.
I believe is massive context, but targetted context. It has to be valuable, and important.
My agents are large. My skills are large. Etc etc.
by jason-richar15
0 subcomment
- [dead]
by alan-jordan13
0 subcomment
- [dead]
- What is a good Claude.md?
- Even better: learn to code yourself.