Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the description adds little on safety. It adds the useful scope 'one exact track', but does not disclose return shape, ordering, or behavior when the track has no clips; with annotations covering the main risk, 3 is appropriate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.