One move. A travel that reaches its framing. A duration inside its band.

Preset video platforms key on named moves - Dolly In, Crash Zoom Out, Snorricam, Bullet Time - which makes a whole class of mistake mechanically detectable. Stacking moves is the single biggest cause of jitter and failed generations. A 10cm pull cannot land a full-body reveal. A flash establishing shot is half a second, not a full one. And zoom is a lens change, not a camera that travels.

The checker is free and needs no account. It runs in your browser over a 28-move catalogue and names every finding against the rule it breaks. Every lane also ships a worked example that costs nothing. Writing a prompt needs credits.