Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is only 40% (agentId, updates, expectedRevision lack schema descriptions), so the description must compensate. It does add value: idempotencyKey must be reused on retry, expectedRevision drives REVISION_CONFLICT handling, updates preserves omitted fields, and group IDs must be resolved via list_contact_groups. Reasonably strong compensation, though the nested update fields are left to the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.