Bus timetable

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

Annotations only cover readOnly and openWorld, so the description earns credit for disclosing that frequency-based routes return a headway rather than a departure list, and that some cities have no timetable data at all. It does not say what happens when the route has no service on the requested date or how large a result set typically is, leaving a small gap.

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 plus a worked example, with the core capability and the sibling routing front-loaded. The Kaohsiung note is a useful fragment rather than filler, though the sentence packing several clauses makes it slightly dense on first read.

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?

With seven parameters, an enum, and no output schema, the definition covers mode, scope, the live-vs-scheduled split, data-availability caveats, and a sample invocation — enough to call it correctly. The shape of the frequency-mode response is only implied, which is the remaining shortfall for a tool lacking an output schema.

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 coverage is 100%, so the baseline is 3; the description lifts it by clarifying that departures are taken from the first stop unless a stop is supplied, and by giving a concrete cross-parameter example (city "InterCity", routeName "1610", stop "臺北轉運站") that demonstrates the intercity mode and Chinese stop names in one call.

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 — scheduled departures of a bus route on a given day — plus two output modes (departure list from a stop, or frequency/headway for frequency-based routes). It explicitly separates itself from the live-arrivals sibling, so an agent can pick it 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 positive guidance (planning ahead, coaches and rural routes) and names the alternative with its selection condition ('use bus_eta for live arrivals'). It also supplies a negative constraint — Kaohsiung publishes no timetables — which prevents a guaranteed-empty call.

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