Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the tool as read-only, idempotent, and non-destructive, so the description is not burdened with safety disclosure. It adds minor context like freshness ('最新') and price components, but does not disclose return format, error behavior, or whether results are cached. This is adequate but not rich.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.