Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the bar is lower. The description still adds real behavioral value by disclosing the state transition to drafts and the non-destructive, recoverable nature of the outcome; it does not cover auth requirements or error cases such as unscheduling a post that isn't scheduled.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.