Search bus routes

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description usefully adds that matching is substring-based across three fields and enumerates the returned data (endpoints, operators, fare), which matters because there is no output schema. It does not mention result ordering or how the limit interacts with matching, so not a 5.

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?

Three short sentences: what it matches, why to use it, and worked examples. The purpose and the disambiguating guidance are front-loaded, and nothing is repeated from 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?

For a read-only two-required-parameter search with no output schema, the description covers matching behavior, return contents and its place in the tool chain. Only minor gaps remain, such as result ordering or what happens when nothing matches.

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%, with city, keyword and limit all documented including the InterCity special case and the default limit of 20. The description's example city/keyword pairs reinforce usage but add no semantics beyond the schema, so the baseline of 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 and resource plus the matching semantics (name, first or last stop contains keyword) and what the results carry (endpoints, operators, fare). It also positions itself relative to the other bus tools, so an agent can tell it apart from bus_route_stops, bus_eta and bus_positions without opening their schemas.

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?

'Use it to find the exact route name the other bus tools need' gives clear, actionable when-to-use guidance and explains the downstream role in a workflow. Two concrete example invocations (Taipei/307, InterCity/1610) make the call pattern obvious. No explicit exclusions or named alternatives are given, which keeps it below a 5.

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