THE SHORT ANSWER
Three things, above a collapsed block that holds everything else: what changed, what was not checked, and what the reader is being asked to decide. Simon Willison's November 9, 2026 post folds the agent's full description inside a details element labeled with the model and effort level and puts a short human-chosen opener on top. By his own list the agent's essay holds the steps taken to verify, so the verification is now under the fold, and the five example openers he quotes all describe the change. The second line should come from the run's record, not the agent's prose. In my own repository 343 of 401 commits since September 1 carry an agent co-author line, and the run reports are the long ones: last week's five creator scan digests ran 66,349 to 82,798 characters with the list of what was not read starting as late as character 74,764. The November 9 digest is the first to lead with it.