Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so each parameter (url, host, json, zone) already has a description. The tool description, however, does not clarify which parameter(s) are relevant for fetching robots.txt. It only says 'fetch a public robots.txt,' leaving the agent to guess whether to use url or host. This adds no value beyond the schema, so baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.