Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of behavioral disclosure. It states that the tool stops all clips in a scene, which is a meaningful multi-clip action, but does not disclose potential side effects (e.g., playback state, follow actions, invalid index handling).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.