get_phone_numberFetch a phone number record by its unique ID to access details like number, status, and configuration. Use this to retrieve specific phone number information when you know the ID.
Fetch one phone number record by id.
Requires scope phone_numbers:read.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | The record id, e.g. "6a96a3ead6e886d42462dd3e". |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark it read-only, idempotent, and non-destructive, so the description only needs to add extra context. It adds the required scope (`phone_numbers:read`), which is genuinely useful and goes beyond what annotations express. No contradictions with annotations.
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 short sentences; the core action is front-loaded and the scope requirement is a separate, clearly marked note. Every sentence earns its place with no wasted words.
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 single-record read with rich annotations and 100% schema coverage, the description plus schema leave no critical gaps. The only omission is explicit 404/not-found behavior, which is minor and conventional for a fetch-by-id 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 coverage is 100%, with the id parameter already described and given an example. The description adds no new parameter semantics beyond restating that lookup is by id, so baseline 3 is appropriate.
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 names a specific verb ('Fetch'), a specific resource ('one phone number record'), and the lookup key ('by id'), clearly distinguishing it from list_phone_numbers, which returns collections. Nothing ambiguous about what this tool does.
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?
Usage context is implied: you call this when you have a phone number record id and want that single record. It does not explicitly contrast with list_phone_numbers or mention when not to use it, leaving the agent to infer from sibling names.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.