list_transit_operators

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

With no annotations, the description carries the full burden of behavioral disclosure. It only says 'display all operators' and does not mention output format, pagination, data scope, or any limitations. There is no indication of whether it is a read-only operation or if any authentication is needed.

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?

The description is a single, well-front-loaded sentence that conveys the core purpose and available filter types. There is no redundant or irrelevant information.

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?

For a list tool with no output schema and no annotations, the description gives the essential purpose and filter types, but it omits the language parameter and details about the returned data structure. It is minimally sufficient but has clear gaps for a complete understanding.

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 0%, so the description must compensate. It adds meaning for type_filter by listing the ferries/train types, but it does not explain the language parameter at all. The enum values in the schema are partially clarified by the Japanese descriptions.

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?

The description clearly states it lists transit operators (交通事業者一覧) and specifies the types (rail, AGT, monorail, tram, ferry) with a type filter. It is a specific verb+resource pair, but it does not explicitly differentiate from sibling tools like list_ferry_ports or get_operator_routes.

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?

No guidance is provided on when to use this tool versus alternatives. The description mentions a type filter but does not state scenarios or exclusions, such as when to prefer search_route or get_operator_routes.

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