Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, indicating safe, read-only access. Description adds that the result includes contacts and open cases count, which is useful but does not provide deeper behavioral context like pagination, error conditions, or performance. With annotations covering safety, the description adds moderate value.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.