Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation profile is covered. The description adds real value beyond that: it names the required permission level (full workspace write access) and clarifies the blast radius (tag assignments removed, documents preserved).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.