Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (destructiveHint=true, readOnlyHint=false), the description adds meaningful behavioral detail: the automation is stopped, moved to archive, remains visible via list_archive, and can be restored with rescheduling. This clarifies the reversible nature of the operation and is not available from annotations alone.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.