Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It does disclose two important constraints: moving into private areas is forbidden and the destination must not already exist. However, it does not describe side effects such as whether old paths are invalidated, error behavior, or reversibility, leaving the mutation behavior only partially transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.