list_configured_countries

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

No annotations are provided, so the description carries the behavioral disclosure burden. It does disclose the key semantic — it lists only countries with API credentials configured, implying a read-only inspection of server configuration. However, it does not say whether the list reflects static configuration or live credential validation, nor what happens when no countries are configured. Adequate but minimal for a zero-param read-only tool.

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-constructed sentence that conveys the resource, the selection criterion, and the scope with zero wasted words. The key information is front-loaded and nothing extraneous is included.

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 parameterless list tool with no output schema, the description tells an agent what it will get (countries with configured API credentials) and the scope (this MCP server). The only minor gap is the lack of any hint about the return format — e.g., country codes, names, or objects — which would be nice given no output schema exists.

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 tool has zero parameters, and per the rubric the baseline is 4. The description correctly implies the tool needs no arguments; the empty schema requires no additional explanation. Nothing about parameters is missing.

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?

Uses a specific verb and resource: 'List countries configured with API credentials in this MCP server.' It clearly distinguishes from payment-focused siblings like get_balance, create_transfer, and initialize_payment. Even without opening the schema, an agent knows exactly what this tool returns.

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?

There is no explicit when-to-use or when-not-to-use statement, but the context is unmistakable: it is the only discovery/list tool among payment and transfer operations. The intended use — checking which countries are supported/configred before initiating payments — is clearly implied by the description, though no exclusions or alternatives are named.

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