The fully automated feedback on every PR is the useful part, but a bug-hunting agent needs its own measurement. Plant a handful of known defects in a staging copy of an app, such as a disabled button state or a wrong total after a coupon, and check how many the agent reports across repeated runs on the same build. If it finds a defect one run and misses it the next, the run-to-run variance matters more than the headline catch rate. I'd also want it to report false alarms separately, so a reviewer can see how much time each PR comment actually costs.