Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnlyHint and idempotentHint, so safety is covered. The description adds useful behavioral context: the tool is heuristic ('parece encajar mejor') and explicitly explains to the user that this is only an initial orientation, setting expectations about the recommendation's nature.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.