search_ferrySearch ferry and water bus routes between two ports and check timetables. Force response language with ja, en, or zh.
フェリー／水上バス航路検索 - 港間の航路と時刻表を検索。language（ja/en/zh）指定で応答言語を強制可能。
| Name | Required | Description | Default |
|---|---|---|---|
| to_port | Yes | 到着港 | |
| language | No | 応答言語の強制指定（省略時は港名から自動判定） | |
| from_port | Yes | 出発港 |
Changes observed during successful MCP inspections.
v2.58.7Input schema / $schemaAdded value: +"http://json-schema.org/draft-07/schema#"Input schema / additionalPropertiesAdded value: +falseInput schema / properties / languageAdded value: +{
+ "description": "応答言語の強制指定（省略時は港名から自動判定）",
+ "enum": [
+ "ja",
+ "en",
+ "zh"
+ ],
+ "type": "string"
+}v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered. The description adds only the language-forcing behavior, which is also covered by the schema, so it contributes little behavioral context beyond what structured fields provide.
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?
A single compact sentence with the resource and scope front-loaded, followed by the language clause. No filler, though the claim structure is dense and slightly terse for an agent needing port-input format details.
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?
There is no output schema, and annotations already cover the safety profile, so the description mainly needs to convey input expectations and scope. It covers scope adequately but omits what port identifiers are accepted (names vs codes), geographic coverage, and whether results include fares or only schedules.
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%, so from_port, to_port, and language are all documented with descriptions and an enum in the schema. The description restates the language parameter's effect without adding syntax, format, or code-system guidance (e.g., whether port names or codes are expected). Baseline 3 applies when the schema does the heavy lifting.
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 states a specific verb (検索) and resource (フェリー／水上バス航路), and adds scope: routes and timetables between ports (港間の航路と時刻表). The ferry/water-bus domain implicitly separates it from siblings like search_bus, search_flight, and search_route, though no sibling is named explicitly.
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?
Usage is implied by the domain—an agent can infer this is the ferry-route lookup equivalent of search_bus/search_flight—but there is no explicit when-to-use, when-not-to-use, or alternative tool named. No prerequisites or conditions are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.