How do you review work from three coding agents at once?

Most days I have three coding agents working on the same repo, each on its own branch. Starting them takes a minute. Reviewing what they did takes the rest of the afternoon.

The summaries they write at the end are confident and usually a little wrong. "Added tests" sometimes means one test. "Refactored the handler" sometimes means it also renamed a function three other files call.

What works for me so far: I read the diff before the summary, I run the checks myself before merging, and I merge one branch at a time, so a conflict shows up while I still remember what each agent was asked to do.

What still doesn't work: when two agents finish at the same time, I start skimming. And skimming is exactly when the renamed function gets through.

How do you review agent output? One branch at a time, a checklist, a second agent reviewing the first, or something else? I'd especially like to hear from anyone who has stopped reading the summaries altogether.