search_ferry

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

No annotations are provided, so the description must fully disclose behavioral traits. It only states that the tool searches routes and timetables, but does not describe output format, whether it returns real-time or schedule data, pagination, or any limitations. This is insufficient for a tool with no annotation support.

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 that is concise and front-loaded with the core action and scope. Every word contributes to the purpose, with no unnecessary information.

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 search tool with no output schema, the description adequately conveys the basic purpose. However, it does not clarify differences from overlapping tools like get_timetable or describe what the search returns, leaving some contextual gaps.

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 already provides descriptions for both parameters (from_port: 出発港, to_port: 到着港) with 100% coverage. The description's reference to '港間' adds no new semantic meaning beyond what the schema already states, so it meets the baseline without enhancing parameter understanding.

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 'フェリー／水上バス航路検索 - 港間の航路と時刻表を検索' clearly states the tool's purpose: searching ferry/water bus routes and timetables between ports. It uses a specific verb (検索) and a well-defined resource (routes and timetables), and the mention of '港間' (between ports) distinguishes it from generic route search tools like search_route and search_bus.

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 should be used when searching for ferry or water bus routes between ports, but it does not explicitly state when to use it over alternatives such as get_timetable or search_route. No exclusions or alternative references are provided, so usage guidance is only implied, not explicit.

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