A 1,000-line CLAUDE.md burns 7,000-10,000 tokens per turn on instructions the model already knows. Skills using progressive disclosure cut that to ~50 tokens. A 1,000-line CLAUDE.md burns 7,000–10,000 tokens per turn in Claude Code. That's instructions the model already knows from reading the codebase, according to a detailed analysis by developer Abd Rahman Saber Abdo. Key facts 1,000-line CLAUDE.md = 7,000-10,000 tokens per turn. Skills load ~50 tokens vs 7K+ for CLAUDE.md. 95% of agent setups don't need a CLAUDE.md. Model at 85% context utilization is measurably worse than at 30%. Recursive skill building: workflow → run → skill → failure → fix. The ritual is everywhere in AI coding agents: you create a CLAUDE.md, list your framework, coding style, and response tone. It feels productive. But it's likely making your agent dumber and wasting money, argues developer Abd Rahman Saber Abdo in a technical deep-dive [According to the source].…