Nothing, because you can’t trust PR authors to disclose use of AI tools. This proposal is wishful thinking.
At this point you have to assume every PR is made with AI tools. Anytime somebody discloses usage by a “co-authored-by” field or otherwise, they are extending courtesy towards the PR reviewers. But it’s pretty easy to not do that and pretty naive for PR reviewers to assume a lack of disclosure equals lack of tool usage.
The only way to ensure lack of AI usage at this point is to close public pull requests and vet the core developer team against having AI tools enabled during their work. This is unreasonable and we won’t be doing that.
To be clear, I’m just one guy on the team, and emphatically not on the Steering Council. They might see it in a different way. But as somebody who does do review stuff all the time, I need to think about any PR reviewed these days as possibly adversarial, and this extends way back to the story of the xz backdoor, so it’s not specific to LLM usage.