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. While it mentions the tool's purpose and usage context, it doesn't describe important behavioral aspects: whether this is a read-only lookup (implied but not stated), what happens with invalid city names, whether there are rate limits or authentication requirements, or what the return format looks like. For a mapping tool with zero annotation coverage, this represents significant gaps in behavioral transparency.

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 two sentences that efficiently convey the core functionality and usage context. The first sentence states the purpose, and the second provides the specific usage scenario. There's no wasted language, and the information is front-loaded with the primary function. However, the structure could be slightly improved by explicitly separating purpose from usage guidelines.

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 tool's moderate complexity (single parameter mapping function), no annotations, no output schema, and 0% schema description coverage, the description is minimally adequate but has clear gaps. It covers the basic purpose and usage context but lacks details about error handling, return format, parameter constraints, and differentiation from similar sibling tools. For a lookup tool that serves as a parameter preparation step for other interfaces, more complete documentation would be helpful.

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 has 0% description coverage for its single parameter 'citys', so the description must compensate. It adds meaningful context by specifying that the parameter accepts '中文城市名' (Chinese city names) and that it's used when users provide city names as departure/destination points. However, it doesn't clarify whether this accepts single cities or multiple cities (despite the plural 'citys' parameter name), nor does it provide examples or format requirements. The description adds some value but doesn't fully 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: querying for station_code using Chinese city names. It specifies the verb '查询' (query) and resource 'station_code', and indicates the context of preparing parameters for departure/destination interfaces. However, it doesn't explicitly differentiate from sibling tools like 'get-station-code-by-names' or 'get-stations-code-in-city', which appears to serve similar mapping functions.

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 clear context for when to use this tool: when users provide city names as departure or destination points to prepare station_code parameters for other interfaces. It specifies the input format (Chinese city names) and the intended downstream use. However, it doesn't explicitly state when NOT to use it or mention alternatives among the sibling tools, which limits the guidance for tool selection.

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