Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations present, the description carries the full burden of behavioral disclosure. It merely says 'lists' which implies read-only, but doesn't mention performance characteristics, whether effects are returned in any specific order, or whether availability depends on current selection/context. For a read-only list operation this is minimal but could be more explicit about what 'video effects' includes (vs audio/transitions).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.