unassign_number

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

Since there are no annotations, the description carries the burden of disclosure. It transparently states that calls will not be answered, the number still exists, and it can be reassigned later. It could go further by mentioning permissions or effects on active calls, but the key side effects are clearly described.

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?

Three concise sentences front-load the purpose, then provide a clear use-case list. Every sentence adds meaningful information with no filler or repetition of the schema.

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 simple single-parameter operation, an output schema is present, and the description explains the outcome, persistence, and reassignment. Minor gaps remain around parameter acquisition and active-call behavior, but for this tool's complexity the description is largely complete.

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 schema has 0% description coverage, so the description must compensate, but it never explicitly explains phone_number_id. The agent can infer that the parameter identifies the phone number from the tool name and context, yet no guidance is given on how to obtain the ID or validate it.

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 opens with a specific verb and resource: 'Remove the agent from a phone number' and clearly states the consequence ('inbound calls stop being answered'). This distinguishes the tool from the sibling assign_number by describing the removal and the fact that the number remains reassignable.

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 gives explicit use cases: retiring a number, switching agents (with the concrete instruction to unassign then call assign_number), or taking a number offline for maintenance. This is exactly the kind of when-to-use guidance that helps an agent choose correctly among siblings.

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