get_coverage_stats

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

Discloses that the endpoint is free and requires no API key, which is valuable context beyond the tool's basic function. No annotations exist, so description carries full burden; it adequately covers cost/authentication behavior.

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?

Two sentences: first states purpose and returns, second provides usage guidance and a key behavioral note. No wasted words, information is front-loaded.

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 tool with no parameters and no output schema, the description adequately explains purpose, usage, and return data. It is complete enough for an agent to decide when to invoke.

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?

No parameters exist; schema coverage is 100% by default. The description adds value by explaining what the tool returns, fulfilling the baseline for a zero-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 clearly states it gets coverage statistics for the Orizn Visa database, listing specific metrics (passport-destination pairs, countries, languages). It distinguishes from sibling tools like check_visa_requirement by focusing on overall scope rather than individual queries.

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?

Explicitly states when to use: 'when the user asks about the size, scope, or coverage of the visa database.' This provides clear guidance for agent selection.

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