AGENTS.md Mastery

Overview

AGENTS.md is pseudo-memory loaded at session start. Every line shapes agent behavior for the entire session. Quality beats quantity. Write for agents, not humans.

Unlike code comments or READMEs, AGENTS.md entries persist across all agent sessions. A bad entry misleads agents hundreds of times. A missing entry causes the same mistake repeatedly.

Core principle: Optimize for agent comprehension and behavioral change, not human readability.

The Iron Law

EVERY ENTRY MUST CHANGE AGENT BEHAVIOR