Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so safety and side-effect behavior need no restating. The description adds the useful note that results come from an external profile directory (open-world), but says nothing about result ordering, matching semantics (substring vs exact), or truncation beyond what the schema's limit field implies.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.