Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations and no output schema, the description carries real weight, and it does disclose the return payload (chat id, name, directories) plus how to reuse names as chat_id. It omits whether the call is read-only (implied by 'Show' but unstated), whether the list is paginated, and whether it reflects permissions of the caller.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.