Why Claude Code Ignores Your CLAUDE.md (And How to Fix It)
You wrote a detailed CLAUDE.md, and Claude Code still gets things wrong — using the wrong convention, touching files it should not, ignoring rules you clearly wrote down. The cause is almost never that the rules are missing. It is that they are buried.
The Over-Specified File Problem
CLAUDE.md loads into Claude's context every single session, and performance degrades as that context fills. When a file grows too long, something counterintuitive happens: Claude starts ignoring parts of it. The important rules get lost in the noise, and the genuinely critical instructions are buried too deep to reliably influence output. A bloated file does not just waste tokens — it actively makes Claude less reliable.
Why Longer Feels Safer But Is Not
Teams start with good intentions: "let us put everything relevant in here." They end up with massive files that are impossible to scan, full of duplication, and so noisy that the signal of the truly important rules is effectively zero. More content feels like more control, but past a point it is the opposite.
The Fix: Prune Ruthlessly
Run every line through one question: "If I remove this, will Claude make a mistake?" If the answer is no, the line is noise — delete it. If something only matters in a specific situation rather than always, it does not belong in the always-loaded file at all; it belongs in a skill or a subdirectory file that loads on demand.
Let Claude Fetch What It Needs
Instead of embedding everything, tell Claude how to pull context when it needs it. Rather than pasting an entire API guide into the file, point to it conditionally — "for Stripe work, read the Stripe guide." That costs almost nothing until the moment it is needed, keeping the always-loaded context lean.
The Result
A pruned CLAUDE.md is often a third of the length and many times more effective. The rules that matter are no longer competing with noise, so Claude actually follows them. Brevity here is not a style preference — it is a performance requirement.