Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only indicate readOnly=false, openWorld=false, idempotent=false, destructive=false. The description adds meaningful behavioral detail: it restores the previous draft, clears the stash, surfaces supersededDraft and retryScoredWorse in review cards, and returns restored:false when no stash exists. This is exactly the kind of non-obvious state behavior an agent needs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.