Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description must carry the full behavioral burden. The word 'List' clearly indicates a read-only, non-destructive operation, which is valuable. However, it does not disclose whether results are paginated, what fields are returned, or any account-level permission constraints, leaving some behavioral ambiguity.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.