Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and says almost nothing: not how many rows are returned, not the tie-breaking behavior, not whether the column must be numeric (only implied), and not that the result is bounded. It does convey the descending-first direction, which is a small but real disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.