country_listFind available countries and country codes for a selected proxy product. Specify the product type to retrieve its supported country list and codes.
查询某产品可选的国家及编码。
| Name | Required | Description | Default |
|---|---|---|---|
| product | Yes | 产品：dynamic-no-expiry=动态住宅流量（永久），dynamic-monthly=动态住宅流量（期限），static-standard=静态住宅（非原生），static-native=静态住宅（原生），static-isp-native=静态住宅（运营商原生），static-ipv6=静态住宅（IPv6），datacenter=数据中心 |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already establish read-only, idempotent, and non-destructive behavior. The description adds that the result is product-specific and includes country codes, but does not mention pagination, output shape, or any other runtime behavior; acceptable for a simple list but not rich.
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 that is front-loaded with the action and object and contains no filler. It is appropriately sized for a one-parameter read-only query tool.
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?
With one required parameter fully documented in the schema, read-only/idempotent annotations, and no output schema, the description's statement of what is returned (countries and codes for a product) is sufficient for an agent to invoke the tool correctly.
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 covers 100% of the single parameter with a detailed enum and per-value explanations, so the description needs to add little. It only restates the product dependency ('某产品') and does not add semantic detail beyond the schema.
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 clear action ('查询' - query) and resource ('某产品可选的国家及编码' - countries and codes available for a product), so an agent knows exactly what the tool does. It does not explicitly contrast itself with sibling tools like state_list or city_list, relying on the resource term and name rather than an explicit differentiation.
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 is for retrieving selectable countries for a product from the enumerated product values, but it gives no explicit when-to-use vs alternatives or exclusions. An agent can infer usage from context, but the description does not guide selection among the sibling listing tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.