30 practical rules for keeping Claude Code useful and controlled

Claude Code works better when its setup stays small and purposeful. A long CLAUDE.md is read often, so it can waste money and make important rules harder for the model to notice. Each line should stay only if removing it would likely cause Claude to make a real mistake. Stable project facts belong in CLAUDE.md, while changing status notes should live somewhere that can be updated separately.

Repeated failures should be fixed with structure, such as hooks, tool limits, and file permissions, instead of only adding more written instructions. Simple repeated work should be handled by scripts, while agents and skills should be used for tasks that need judgment. Dangerous actions should be blocked, but recoverable mistakes can be allowed and observed so the setup improves from real evidence. Splitting roles between builder, evaluator, coordinator, planner, and verifier can reduce conflicts, especially when one agent might otherwise judge its own work.

Memory can become stale because it grows automatically, so durable facts should be separated from temporary claims and cleaned up over time. Guardrails should be reviewed after model upgrades because rules that once helped may become extra noise as the model improves.