list_servicesList data services offered by this server: ids, countries, prices, and required params. Optional country filter (ISO 3166-1 alpha-2, e.g. "AU", "US", "GB"). Optional category filter (e.g. "crime", "weather", "econ"). Free.
| Name | Required | Description | Default |
|---|---|---|---|
| country | No | ISO 3166-1 alpha-2 country code filter, e.g. "AU" | |
| category | No | Category filter, e.g. "crime", "weather", "econ". Use list_categories to see available categories. |
Changes observed during successful MCP inspections.
Input schema / properties / categoryAdded value: +{
+ "description": "Category filter, e.g. \"crime\", \"weather\", \"econ\". Use list_categories to see available categories.",
+ "type": "string"
+}Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
readOnlyHint=true already establishes this is a safe read, but the description adds two pieces of behavioral context beyond annotations: the tool is "Free" (no cost to invoke) and it returns ids, countries, prices, and required params. Since there is no output schema, disclosing the return fields is genuinely useful. It stops short of describing pagination or result-size limits.
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 well-ordered sentence: purpose and return contents first, then the two optional filters, then the cost marker. Every clause carries information and nothing is padded.
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 no output schema, the description compensates by naming the returned fields, and it covers both optional filters and the cost model. It is nearly complete for a simple read-only list tool; only pagination/result-size behavior and explicit sibling routing are absent.
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 both parameters are already documented with format examples in the schema itself. The description largely restates the filters and their examples (ISO 3166-1 alpha-2, "crime"/"weather"/"econ") without adding syntax or semantics beyond that. 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 and resource ("List data services offered by this server") and enumerates what comes back (ids, countries, prices, required params). It is clearly a listing tool, though it does not explicitly contrast itself with siblings like search_services or get_catalog, leaving that distinction to inference.
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 through the optional filter descriptions (country, category), which tell the agent how to narrow results. However, there is no explicit when-to-use guidance, no mention of when to prefer search_services or get_catalog, and no stated prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.