Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare a non-read-only, non-destructive, non-idempotent, closed-world write. The description adds real behavioral context beyond that: exactly what content travels with the copy (sheet structure and rows, folder contents) and that ids must be sourced from workspace.structure. It omits naming/collision behavior for the new item, whether permissions are inherited, and whether repeated calls pile up duplicates.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.