Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so baseline is 3. The description adds meaning beyond the schema by explaining the effect of outcome='not_interested' (explicit decline, stage movement, funnel treatment) and by naming the exact search tools for obtaining message_id, though channel and on_behalf_of semantics remain schema-only.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.