Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the safety profile is supplied. The description adds real value with 'This can change who has access', which tells the agent the permission surface is affected — but it omits the concurrency/revision-check behavior implied by expectedRevision and says nothing about what happens to shares on the document.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.