Part 2: When Nobody Grades Their Own Homework

TL;DR Some things can't be checked with a number, like whether an animation feels right. So a second, read-only agent grades the first one against a written rubric it is not allowed to edit. In my run the reviewer rejected the builder three times, and the most interesting problem it caught was in the test evidence, not the code. In Part 1 I built a loop that chased a number, frames per second. But most of what we care about in software is not a number. "Does this region switch feel good?" has no assert. You cannot write expect(feelsRight).toBe(true) . So this part is about how you check quality when there is nothing to measure. The approach I used is a second agent that grades the first one against a written rubric. In my run the reviewer turned the builder down three times before it approved anything, and the most interesting problem it found was not in the code at all. A quick reminder of the definition, since this is Part 2 of 3: a loop is an external script that runs the agent, a separate check the agent cannot edit decides pass or fail, and it repeats until it passes or hits a limit. In Part 1 the check was a Playwright test. Here the check is another agent. The problem this loop solves In the browser you can switch regions, say from Tamil to Korean, which swaps out hundreds of posters at once. Done badly, the grid flashes blank and jumps around. Done well, it fades from one set to the next, keeps its layout, shows a loading state, and puts you back at the top. "Done well" is subjective, which is the kind of thing you cannot unit-test. So I wrote it down as a rubric and had a second agent apply it. The bar: a rubric a person owns The rubric is seven plain-English checks in a file, and the first line is the one that matters: Overall APPROVED requires every item PASS. This file is human-owned. Only a person changes the bar. The seven items are things like a crossfade instead of a flash, no layout shift, a visible loading state, posters that stay 2:3, and landing