Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of behavioral disclosure. It communicates that the tool returns a read-only set of company facts and lists those facts, which is sufficient for a no-parameter information lookup. It does not detail response structure, but the enumeration partially compensates.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.