Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses the contents of the provenance information, but does not describe the return format, whether it is a static metadata lookup, or any failure cases. This is adequate for a simple metadata tool but not richly transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.