Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=true, indicating a safe read operation. The description adds that it 'returns matched intent topics', hinting at output behavior, but doesn't disclose details like rate limits, authentication needs, or processing time. Since annotations cover safety, the description provides minimal extra context, meeting the lower bar but not enriching behavioral understanding significantly.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.