Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only declare readOnlyHint and openWorldHint; the description goes further and discloses the shape of the result (apps chained with →, what it does, the n8n workflow JSON, the blanks to fill, accounts to connect) plus supplementary public templates. No auth, rate-limit, or failure behavior is mentioned, and nothing contradicts the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.