Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnly/idempotent/non-destructive annotations, the description discloses significant behavior: it names unpriced positions instead of silently assessing a partial portfolio, breaches produce proposals that require human decisions, approving a proposal records the decision and executes nothing, TWMD has no order path, and pricing is point-in-time official data. This is far richer than annotation-only disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.