Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive), but the description adds genuinely new context: it is a curated Subastech knowledge base sourced from BOE, requires no account, is not legal advice, and notably is 'sin modelo de lenguaje' (not an LLM). That last point meaningfully sets expectations about output style.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.