transit_route_plan

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

With readOnlyHint and openWorldHint annotations, the safety profile is already disclosed. The description adds value by specifying the route includes transfers, duration, and fare. It does not disclose any side effects or limitations, but given the annotation coverage, it adds appropriate context.

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?

One concise sentence that states the action and key outputs without fluff, front-loaded with the verb 'Plan'.

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 simple two-parameter tool with no output schema, the description adequately specifies what the tool returns (transfers, duration, fare) and the input scope (Japanese train stations). However, it doesn't mention error handling for unknown stations or whether the route is optimal, but for a tool of this simplicity, the description is nearly complete.

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?

The input schema fully documents both parameters with 'Origin station name' and 'Destination station name' (100% coverage). The description adds the stipulation that these are Japanese train stations, providing a small increment of meaning beyond the schema. At baseline 3 due to high schema coverage, the minor addition still merits 3.

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 uses a specific verb 'Plan' and resource 'route between two Japanese train stations', and lists expected outputs (transfers, duration, fare). It clearly distinguishes from sibling tools like transit_station_status and transit_stations_search. However, it does not explicitly differentiate from transit_alternative_routes, which also plans 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?

The description implies the tool is used to plan a route between two stations, but it provides no guidance on when to prefer this tool over transit_alternative_routes or how to handle station name validation (e.g., using transit_stations_search). No exclusions or alternatives are mentioned.

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