Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden but only states the action without disclosing behavioral traits like authentication needs, rate limits, pagination, or response format. It lacks details on what 'list' entails, such as whether it returns all PRs or requires parameters for filtering.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.