Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, and it discloses almost nothing: no scope (workbook- vs. session-level), no persistence semantics, no statement of whether existing geocoded fields are affected, and no permission requirements. It only conveys that this is a setter influencing generated map coordinates.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.