Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already mark this as destructive and read-write, and the description builds on that by stating exactly what changes (body, format, title) and what stays the same (URL, counts, expiry). It also discloses the no-op behavior and the overwrite-protection semantics of ifVersion/ifSha, which goes well beyond the structured fields.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.