Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already establish read-only, idempotent, non-destructive behavior, so the description adds value by explaining the id contract: rows are numbered from 1 per account, safe to display, and expected as identifiers by other tools. This is useful behavioral context that structured annotations do not convey.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.