Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description does add one useful behavioral nuance beyond the structured fields: the return may be a member OR a system user, implying an authentication context and a variable entity type. It says nothing about auth failure behavior or what fields come back.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.