Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations and no output schema, the description carries the full burden, and it does disclose the four things returned (columns, numeric indicators, row count, provenance banner). It stays silent on read-only/permission expectations, response format, and sizing behavior for a dataset tool, so it 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.