Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full disclosure burden, and it does add real behavioral context: grouping commas and currency symbols are parsed, and non-numeric rows are excluded but counted. It stops short of describing the response shape, where the excluded-row count is surfaced, or what happens if the named column does not exist or is non-numeric.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.