Retrieve World Bank country details—region, income level, and capital city—in one query.
List World Bank countries with region, income level, and capital city.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v2026.4.11Input schema / additionalPropertiesRemoved value: -falsev2026.3.9Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint false), so the description doesn't need to restate that. It adds value by specifying the content of the list (region, income level, capital city), but it does not disclose any additional behaviors like sorting, pagination, or filtering. Since the tool has no parameters, this is minimal but adequate.
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 a single, efficient sentence that front-loads the action and resource. Every word adds value, with no fluff or repetition.
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?
For a simple, parameterless listing tool with rich annotations covering safety, the description is complete. It clearly states what the tool returns and is sufficient for an agent to invoke it correctly without needing additional details.
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?
There are zero parameters and the schema has full coverage (vacuously). Per the rubric, a baseline of 4 is given for zero-parameter tools. The description adds no parameter information, but none is needed.
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 verb 'List' with the resource 'World Bank countries' and specifies the attributes returned (region, income level, capital city). It is distinct from siblings like wb_search (which searches for specific data) and wb_topics (which lists topics), so an agent can easily differentiate it.
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 its use case: when you need a list of countries with those attributes. However, it does not explicitly mention when not to use it or provide alternatives like wb_search or wb_compare. Given the sibling names, the context is clear but not explicit, so it earns a 3.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.