What problem does this address?

The AI guidelines suggest disclosing if a PR was created with AI assistance.
https://make.wordpress.org/ai/handbook/ai-guidelines/#1-2-transparency-disclose-when-ai-was-used

AI tools can handle this when they assist in creating the description, but
we also do PR's manually and we can need a reminder.

What is your proposed solution?

Add a heading over a new section you can write freely in, or a checkbox?