list_countries

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

No annotations provided. Description lacks behavioral details such as return format, pagination, authentication, or side effects. It only states the action, leaving critical information for invocation absent.

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?

Extremely concise at 5 words, front-loaded with the verb. No unnecessary content, though it could benefit from a slight expansion to include output hints.

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?

No output schema exists, so description should explain return values. It does not. Parameters are covered by schema, but without output context, the description is incomplete for a listing operation.

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 the schema already documents all parameters. The description adds no additional meaning beyond what the schema provides, staying at baseline.

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?

Description clearly states 'List countries' as verb+resource, and adds context '(reference data for travel)'. The name itself implies listing, but the description reinforces it. It distinguishes from siblings like 'get_country' (single) and 'list_cities' (different entity).

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 guidance on when to use this tool vs alternatives (e.g., get_country, list_cities). No when-not or prerequisites mentioned.

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