AGENTS.md in a repository are used to guide development.

That is not entirely true.

It can be. Yes, it provides agents with contexts - rule centralization, commands, conventions - which may be useful for external tooling for a project that runs on code live like this. It isn’t exclusively used for project development, which makes its presence not an indicator.

I see at least one: if the project doesn’t have a clear no-ai policy, then assume it is AIP. But that’s not my proposition at the moment.

Also discussed in the meta thread about this, and what results is projects being called an AI project that are not projects developed with - or even designed to allow interaction with - AI.

Also a non-starter.

I was just asking for a precision, but that’s because I didn’t check archives enough

There is precision in the detailed rules post.

If you want to see the prior meta discussions, you can look at my post history. I don’t often make standalone posts, so they are quick to find.