Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the baseline is 3, but the schema descriptions appear mismatched with the stated purpose: 'HTTPS URL to normalize or cite,' 'JSON text to validate; discarded after the check,' and 'IANA timezone name' do not obviously relate to fetching robots.txt. The description adds no mapping between url/host and the fetch target, leaving the agent unable to determine how to invoke the tool.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.