Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds substantial behavioral context by listing the exact response contents: ex-date, payment date, DPS, imputation %, DRP availability, safety score, cut probability, and payout ratio charts. This goes beyond the structured hints.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.