Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It does add useful behavior details: grouping commas and currency are handled, and non-numeric rows are excluded and counted. However, it leaves ambiguity about the output structure, error handling for missing columns, and precise behavior for empty inputs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.