get_bus_stop_timetable

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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so the safety profile is covered. The description adds one genuinely new behavioral fact — departures retain the provider's order rather than being sorted — but says nothing about pagination behavior, rate limits, or empty-result handling despite exposing limit/offset.

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 with no filler, and the core action plus its input source are front-loaded. The second sentence about available_timetables is slightly cryptic in isolation but still earns its place by describing the returned service metadata.

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?

An output schema exists, so the description does not need to enumerate return fields — yet it spends its second sentence doing largely that, at the cost of the filter and pagination parameters. For a five-parameter tool with zero schema descriptions, the definition is usable but leaves an agent guessing about route/calendar filtering and page sizes.

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 carries the full burden of explaining five parameters. It explains stop_id provenance and mentions 'calendar IDs, and route IDs' only as fields appearing in available_timetables, not as filter parameters, and it never mentions limit or offset at all. The most consequential semantics — what route_id/calendar_id filter and how paging works — are left undocumented.

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 and resource ('Get scheduled Toei bus departures') plus the scope ('from a stop ID'), which cleanly separates it from get_station_timetable (railway) and get_bus_route. It also names search_bus_stops as the producer of the required input, so an agent can identify the tool without opening the schema.

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?

Gives a clear precondition: the stop_id must come from search_bus_stops, which implies the correct call sequence (search first, then fetch timetable). It stops short of explicit exclusions or when-not-to-use guidance versus get_station_timetable, so it is clear context rather than full routing guidance.

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