Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. 'List all smart lists' implies a read-only operation, but it doesn't disclose important behavioral traits like whether this requires authentication, rate limits, pagination behavior (beyond what's in the schema), error conditions, or what format the results will be in. The description is minimal and lacks behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.