12306-MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the limitation of returning only the first ten results, which is valuable context. However, it doesn't describe authentication requirements, rate limits, error conditions, or what the response format looks like. For a query tool with 12 parameters and no annotations, this leaves significant behavioral gaps.

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 appropriately concise with just two sentences in Chinese. The first sentence states the purpose, the second adds an important limitation. There's no wasted text, though it could be more structured with clearer separation of purpose versus constraints.

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?

Given the complexity (12 parameters, 3 required), 0% schema description coverage, no annotations, and no output schema, the description is insufficient. It provides basic purpose and one limitation but doesn't explain parameter usage, return values, or behavioral constraints. For a tool with this many undocumented parameters, the description should do much more to guide proper usage.

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 description coverage is 0%, meaning none of the 12 parameters have descriptions in the schema. The tool description provides no information about any parameters - it doesn't explain what 'date', 'fromStation', 'toStation', 'middleStation', or any other parameters mean or how they should be formatted. The description fails to compensate for the complete lack of schema documentation.

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 the tool's purpose: '查询12306中转余票信息' (query 12306 interline ticket availability). It specifies the resource (interline tickets) and verb (query), though it doesn't explicitly differentiate from sibling tools like 'get-tickets' which might query direct tickets. The purpose is specific but sibling differentiation is implicit rather than explicit.

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 provides no guidance on when to use this tool versus alternatives. There are several sibling tools for station lookups and ticket queries, but no indication of when this interline ticket tool is appropriate versus 'get-tickets' or other alternatives. The only usage context is the limitation '尚且只支持查询前十条' (currently only supports querying the first ten results).

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