search_bus

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 adds useful context by naming the data source (ODPT) and scope (Toei Bus routes/stops), which goes beyond a mere function statement. However, it does not disclose what the tool returns, whether it can be called without parameters, or any limitations, leaving gaps in behavioral transparency for a search tool.

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 sentence with no redundant information. It is concise, front-loaded with the core purpose, and includes a helpful emoji that adds visual clarity without padding. Every word earns its place.

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 tool with one optional parameter and no output schema, the description gives the data source and scope but leaves out important details such as the return format and whether it can be invoked without a bus_stop_name. The absence of an output schema and annotations makes this a noticeable gap, though the description is not misleading.

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 schema fully documents the only parameter, busstop_name, including its partial-match behavior. The description adds no additional parameter semantics. Since schema coverage is 100%, the baseline score of 3 applies, and the description does not need to do extra work.

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 that the tool searches Toei Bus routes and bus stop information from ODPT data (都営バスの路線・バス停情報をODPTデータから検索します). It uses a specific verb (検索/search) and resource (bus routes/stops), distinguishing it from sibling tools like search_ferry or search_route. However, it does not explicitly contrast with search_route or get_operator_routes, so it is not fully differentiating.

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?

There is no explicit guidance on when to use this tool versus alternatives such as search_route or get_operator_routes. The usage is implied by the name 'search_bus' and the description's bus-specific scope, but no conditions or exclusions are provided. This meets the 'implied usage' level, not a higher level with clear context.

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