The idea of a PR is for others to find things that you have a blind spot to, and also leave some paper trail on the thought process. E.g. if something was not fixed, there is a history of a comment and a reason on WHY it wasn't fixed. If you do all that only locally, that context is lost.
We noticed that even after doing this self review loop multiple times, we still find issues (either via other models / tools or via humans that have the "tribal knowledge")
Maybe one day AI will write perfect code and can review itself, but even if it's 0.1% chance it has a bug, or 1 in a million it will do something a bit sinister (like open a backdoor just in case you try to shut it down) - then I really think there is always going to be a need for humans to review something.
You are likely to get better results if you do not use the same model for review that wrote the code. I typically use Opus for code editing and GPT 5.5 for peer review using an automation with skills.
Training set is different between models. If there are gaps in coverage in one model, you want a different model reviewing the work. The second model will its own gaps, but the gap list is not identical.
There’s no evidence of this. I guess you are anthropomorphising models (i.e., it’s good that - different human reviews your code)
However, using two models to generate two reviews easily beats doing one model and one review, as some models seem to "care" more about certain things, but you'll just miss different things if you change the model rather than add more.
Or if you make it "be a security engineer" with particular focus points.
Or make it a grammar nazi, it will find way more typos than without such focus.
Of course all of those "focuses" needs to be in a separate context (agent/subagent) to make it work.
And if you put the review effort into polishing an impl plan, then it doesn't matter which model implements it either.
Like with "SKILL" files in general, it's got to do with Prompt Engineering: https://en.wikipedia.org/wiki/Prompt_engineering#Rationale
They do open source a fair bit of internal tooling, so it’s always interesting to see their approach
We built something similar, it looks for new PRs where the bot is added and does reviews. Makes the code more tuned toward similar rules. I can't assume that a developer run a code review tool himself (just as I don't assume he/she run a build - so we run builds also).
It is just another perspective for code review, besides human. Unfortunately it uses a lot of tokens, and considering that Anthropic, OpenAI and Github Copilot all moved to token based pricing, it is quite a money burner.