Isn't the promise of AI that we don't have to adhere to precise formats? We can just write it down in whatever format makes the most sense to us, and any impedance mismatch is on the machine to figure out?

Just the filename is standardized. The contents aren't, which is exactly right. From the site:

> Are there required fields?

> No. AGENTS.md is just standard Markdown. Use any headings you like; the agent simply parses the text you provide.

No, structure and format matters, even if it may not be precise code syntax

Still need to write it down to make it explicit. The longer the writing gets the more a structured approach is suitable for the human writing and maintaining the instructions.