principle-prove-it-works

Use as soon as you pick up a brief carrying a VERIFY step or acceptance criteria, since finishing it will mean proving it, and again right before declaring a task done or reporting success, and when checking work a delegate says it finished. Requires observing the real artifact (run the scene, render the image, hit the endpoint, read the diff) instead of trusting a green build, a file timestamp, or an agent's own summary.