Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the transparency burden. It discloses output units (degrees), the three window sizes, WGS-84 correction, and the Pro key requirement. It does not explicitly state that the operation is read-only, but the read-oriented nature is implicit and no contradiction exists.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.