For well-intended open source contributions using GenAI, my current rules of thumb are:
* Prefer an issue over a PR (after iterating on the issue, either you or the maintainer can use it as a prompt)
* Only open a PR if the review effort is less than the implementation effort.
Whether the latter is feasible depends on the project, but in one of the projects I'm involved in it's fairly obvious: it's a package manager where the work is typically verifying dependencies and constraints; links to upstream commits etc are a great shortcut for reviewers.
My rules of thumb is much shorter: don't.
The open source world has already been ripped off by AI the last thing they need is for AI to pollute the pedigree of the codebase.
Another great take I found online: "Don't send us a PR, send us the prompt you used to generate the PR."
That's a pretty good framework!
Prompts from issue text makes a lot of sense.
Unfortunately, LLMs generate useless word salad and nonsense even when working on issues text, you absolutely have to reword the writing from scratch otherwise it's just an annoyance and a complete waste of time. Even a good prompt doesn't help this all that much since it's just how the tool works under the hood: it doesn't have a goal of saying anything specific in the clearest possible way and inwardly rewording it until it does, it just writes stuff out that will hopefully end up seeming at least half-coherent. And their code is orders of magnitude worse than even their terrible English prose.