list_countries

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

No annotations or output schema exist, so the description carries the burden of behavioral disclosure. It states the inclusion criterion ('countries with mining listings') and implies a read-only listing operation, but it omits return format, ordering, or pagination behavior such as whether results are sorted alphabetically.

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, front-loaded sentence that conveys the action, subject, and scope without any filler. Every word contributes necessary meaning.

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 zero-parameter, simple list operation with no output schema, the description is adequately complete: it identifies what is returned and the filtering criterion. An explicit note about return format would help, but the low complexity makes this a minor gap.

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 is empty with zero parameters, so there are no parameter semantics to document. The description correctly does not invent parameters, meeting the baseline for a no-parameter tool.

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 uses a specific verb ('Get') and a clear resource ('list of all countries with mining listings on Mine Market'), making its purpose immediately understandable. It also naturally distinguishes itself from sibling tools like list_commodities and search_listings by naming the exact output scope.

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?

No explicit when-to-use guidance or mention of alternatives is present. The intended usage is reasonably implied by the simple enumeration purpose, but there is no direct guidance on when to choose this tool over list_commodities or search_listings.

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