Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare read-only, idempotent, non-destructive behaviour, so the safety profile is covered. The description adds genuinely useful context beyond that: output length (1-3 sentences), tone (short, polite), localisation (traveller's language) and that the output cites the applicable regulation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences, front-loaded with the artifact produced and immediately followed by its scope and constraints. No filler or repetition of the schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given an output schema exists and the 14 parameters are fully documented, the description covers what the agent needs to know about the product. It could say slightly more about available script variants (re-routing vs care vs refund) to help routing, but nothing essential is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% across all 14 parameters, including clear descriptions and enums for type, cause and lang. The description only loosely echoes these (language, the regulation context) without adding syntax or format detail beyond the schema, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+artifact ('writes 1 to 3 short, polite sentences') and the scenario it serves ('for a traveller to say to the airline agent'), which is clear and concrete. It doesn't explicitly differentiate itself from siblings like sos_prepare_message or sos_check_rights, so an agent must infer the boundary, but the purpose itself is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The desk-facing framing ('to say to the airline agent') implies when to use it, and the mention of 're-routing, care or a refund' hints at the situations covered. However, there is no explicit statement of when to pick this over sos_prepare_message or when to call sos_check_rights first.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.