Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint annotation already establishes this is a safe read, and the description adds nothing beyond that — no note on whether inherited/group permissions are included, no permission requirements, no indication of what fields the permission set contains. The description carries no behavior beyond the name.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.