Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context by noting the coverage is 'stored at booking time,' implying it is a historical snapshot rather than live card coverage. It does not discuss auth or rate limits, but those are less important for a low-risk read operation with an output schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.