At least for the specific example given, I want developers to do the commit part themselves, so if their LLM is doing any part of that, its already a mistake IMO.

I had a very quick look at the AI agent guidelines, and nothing about them strikes me as overly burdensome for a human to fix up. So I'd rather just do that myself (if I were a kernel dev).

My main objection is forcing it on developers, it should be up to each dev to configure and manage their own agent. Making it a suggestion is fine, just don't commit it. Also, if developers are using local hosted models, then context may be quite limited, so wasting it on an Agents.MD maybe be unideal.