list_available_phone_numbers

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

With no annotations provided, the description carries full burden for behavioral disclosure. While 'List' implies a read-only operation, the description doesn't mention authentication requirements, rate limits, pagination behavior beyond the parameters, error conditions, or what happens when no numbers match filters. The parameter documentation in the description adds some context but doesn't fully describe the tool's 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?

The description is well-structured with clear sections for Args and Returns. Each parameter gets its own line with brief but informative explanations. The opening statement is direct, though the Returns section is somewhat generic ('Dict[str, Any]: Response data'). Overall, the structure is efficient and easy to parse.

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?

Given the complexity (9 logical parameters despite schema showing 1), no annotations, and no output schema, the description does a good job with parameter documentation but leaves gaps in behavioral context. It doesn't explain what 'available' means, how results are structured, error handling, or authentication requirements. For a tool with rich filtering capabilities but no structured metadata, the description is adequate but incomplete.

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 description provides detailed documentation for 9 parameters (page, page_size, and 7 filter parameters) with clear explanations of their purposes and optionality. This is excellent compensation for the 0% schema description coverage and single parameter in the input schema. The description transforms an opaque 'request' object into well-documented filtering options.

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 states 'List available phone numbers' which is a clear verb+resource combination, but it's somewhat vague about scope and doesn't distinguish from sibling tools like 'list_phone_numbers' (which likely lists already-owned numbers). The purpose is understandable but lacks specificity about what 'available' means in this context.

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 is provided about when to use this tool versus alternatives. There's no mention of prerequisites, when this tool is appropriate, or how it differs from sibling tools like 'list_phone_numbers' or 'initiate_phone_number_order'. The description assumes the user knows when to list available numbers.

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