Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It states what the call returns (full research, abbreviated metrics, AI analysis) which covers the primary behavioral effect. It does not claim any side effects, and the read-only nature is clearly implied. It does not mention rate limits or authentication, but for a research tool that is usually not necessary. The description adds sufficient transparency beyond the raw schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.