Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the burden of conveying behavior. 'Fetch' reasonably implies a read-only operation, and 'along with its internal notes thread' adds useful detail about the response contents. However, the description does not disclose error behavior, authentication needs, or whether this is purely a safe read, which would be valuable given the absence of annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.