Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already include readOnlyHint=true, indicating a safe read operation. Description adds that it returns the 'final' envelope upon completion, but does not disclose behaviors like whether it blocks or requires a valid run state. With annotations present, the description contributes marginally.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.