What to look for, in order
A review has an order: is this the right change, is it designed sensibly, does it work, is it tested, can it be read. Style comes last, because a linter should be handling it.
Agents rarely get syntax wrong. They solve the wrong problem, handle a case nobody asked about and miss the one you meant, add more than you asked for, and weaken a test to get to green. So those go first, and you stop as soon as an early one fails.
Say it to your agent
“Review in this order and stop to tell me if a step fails. 1. Does it do what the brief asked? Quote the brief. 2. What did it change that wasn't asked for? 3. Did any test get weakened or deleted? 4. Which inputs aren't tested? Ignore formatting, because Biome handles that.”