retell_list_phone_numbers

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

No annotations are provided, so the description carries the full burden. It discloses the scope (all phone numbers in the account) but does not explicitly state it is read-only, mention pagination, or describe the return format. The word 'list' implies a safe read operation, though some behavioral details remain implicit.

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 with no wasted words: 'List all phone numbers in your Retell AI account.' It efficiently conveys the tool's purpose without redundancy.

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 list tool with no parameters, no output schema, and no annotations, the description is sufficient. It fully covers the tool's primary function and scope; additional detail about return values is unnecessary since 'list' implies a list of phone numbers.

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 explain. The description does not need to add parameter information; the baseline for zero parameters is 4.

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 the verb 'List' and the resource 'all phone numbers in your Retell AI account', which distinctly separates it from sibling tools like get_phone_number (for a single number) and create/update/delete phone numbers.

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?

The description implies usage (list all phone numbers) but does not explicitly mention when to choose this over alternatives like get_phone_number or list_voices. There is no when-not or alternative guidance, though the simple list operation makes intended use clear.

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