Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It usefully discloses the auth mechanism ('NIP-98 POST with payload = sha256(markdown)'), which is real context beyond the schema, but omits mutation semantics: whether the upload overwrites existing text, permission requirements, and side effects are all unstated.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.