I told my agent it could manage my personal site. It changed the headline.
That was the wrong place to spend the autonomy. The site already had a headline and composition I liked. What had gone stale were the project statements, build log, and field notes. The agent reached for the most visible copy on the page because it had a new positioning sentence and permission to keep the site current. The regression PR is public.
The replacement did not look catastrophically broken. Nothing overlapped or clipped, the mobile page had no horizontal overflow, and the links still worked. The first visual review passed.
The page still looked worse.
On desktop, the new headline was only ten characters longer, but the word lengths forced two extra lines inside a narrow column. The headline grew by 118.72 pixels. The portrait stayed the same height. The whole hero grew by the same 118.72 pixels, and the project section moved down with it. That left a dead column of space below the portrait and turned a balanced block into a long stack of type next to an image that had already ended.
The test was green because it measured the wrong property. It answered one question: does this fit? It never asked whether the page still looked like the site I approved.
I corrected the agent, restored the old hero exactly, and reran the comparison at 1440 by 1100 and 390 by 844. This time the check was differential. The restored screenshots matched the approved desktop and mobile baselines pixel for pixel. The element geometry matched too: headline height, portrait height, hero height, and the point where the project section began.
Then the correction became a contract. Routine automation can update verified project copy, receipt-backed build-log rows, and evidence-backed notes. It cannot change the header, hero, portrait, navigation, CSS, or section order unless I explicitly ask for a redesign. CI now fails if the hero text, portrait, navigation, or CSS changes. Section order is still a review rule, not a check.
That boundary matters more than the wording mistake. Giving an agent authority over a product does not mean every surface should stay mutable. Some decisions are settled. The useful autonomy is inside the areas that benefit from continued judgment: facts that go stale, new work that deserves a receipt, and lessons that have earned an article.
A green visual test can be as misleading as green CI. It may prove only that nothing broke hard enough for the test to notice. If the product already has an approved composition, the next version should be judged against that composition, not against the bare minimum of rendering without overflow.
The human correction was the grader. The durable part was making sure the same correction would not be needed twice.