Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full responsibility. It does not disclose side effects (e.g., whether the source is removed after move), overwrite behavior if destination exists, or permission requirements. For a mutation operation, this is a significant gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.