I guess what I mean is that standardizing this bit of the problem right now feels sort of like XHTML. Many people thought that was a big deal back in the day, but it turned out to be a pointless digression.

Long term you're right though, agents will fetch this all themselves

It's not "long term", it's right now. If your docs are well-written and well-organised, agents can already use them. The most you might need to do is copy your README.md into CLAUDE.md.