More recent models are better at reading and obeying constraints in AGENTS.md/CLAUDE.md.

GPT-5.2-Codex did a bad job of obeying my more detailed AGENTS.md files but GPT-5.3-Codex very evidently follows it well.

Each agent uses a different file, like claude.md etc (maybe you already knew that).

And it requires a bit of prompt engineering like using caps for some stuff (ALWAYS), etc.

You’re not stupid. But the agents.md file is just an md file at the end of the day.

We’ve been acting as if it’s assembly code that the agents execute without question or confusion, but it’s just some more text.