Retrieve your account's phone numbers and DIDs. Filter by number, country, state, city, or type to find specific lines.
List account phone numbers / DIDs. Optional filters: did_number, country, state, city, number_type.
| Name | Required | Description | Default |
|---|---|---|---|
| city | No | City name | |
| state | No | State or region | |
| country | No | Country code (e.g. AU, NZ) | |
| did_number | No | Filter by DID number | |
| number_type | No | Number type filter |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description bears the full burden. The verb 'List' implies a read-only operation, which is helpful, but there is no disclosure of behavior like pagination, sorting, response format, or authentication requirements. It adds minimal behavioral context beyond the action itself.
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 concise sentence that front-loads the core purpose and immediately lists filters. No wasted words; it 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?
For a simple list tool with all optional parameters and no output schema, the description is adequate but not fully complete. It could clarify the distinction from list_available_numbers (owned vs. available) and mention response behavior (e.g., pagination), but for a straightforward read operation, it covers the essentials.
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 each parameter. The description merely lists the same parameter names ('did_number, country, state, city, number_type') without adding additional meaning, context, or examples, keeping it at the 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?
The description clearly states the action ('List') and the resource ('account phone numbers / DIDs'), making the purpose unambiguous. It distinguishes itself from siblings like get_did (specific DID), update_did, and list_available_numbers (available for purchase) by explicitly scoping to account-owned 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?
No explicit guidance on when to use this tool versus alternatives such as list_available_numbers or get_did. The word 'account' implies owned numbers, but there is no direct statement of exclusions or suggested alternatives, leaving the agent to infer usage context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.