Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. 'List all installed' conveys a read-only, non-destructive action implicitly. The description tells the agent this returns template names plus their variable listings, which gives a useful preview of the return structure without needing error-path details for a simple listing operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.