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 sales history' implies a read-only operation, but it doesn't specify whether this is a safe query, what permissions might be required, if there are rate limits, or how results are returned (e.g., paginated format). The description lacks critical behavioral details needed for reliable tool invocation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.