Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are given, so the description must carry the full burden. It only states 'Upload a document' without disclosing whether documents can be overwritten, what happens on success (e.g., returns document ID), or required permissions. This is insufficient for an agent to understand side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.