get_phone_numbers

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

With no annotations provided, the description carries the full behavioral disclosure burden. It clearly signals a read-only listing action and describes the output's content, which is useful. It does not mention pagination, authorization requirements, or edge cases, but the simplicity of the operation makes this a moderate gap rather than a severe one.

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, efficient sentence that front-loads the verb and resource, then lists the key output fields. Every word earns its place, and there is no redundant or vague filler.

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 zero-parameter, low-complexity listing tool, the description is nearly complete: it states scope, action, and return fields. It could add a note about auth requirements, pagination, or empty-result behavior, but those are minor omissions given the tool's simplicity.

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 tool has zero parameters, so parameter semantics are essentially moot; the baseline for this case is 4. The description still adds value by explaining what each returned phone number record contains, compensating for the absence of an output schema.

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 uses a specific verb ('List') with a clear resource ('phone numbers acquired by your organization') and enumerates the returned fields (number, country, capabilities, assigned agent). This clearly differentiates it from sibling tools like get_agents or get_call_logs.

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 its usage context: browsing the organization's phone numbers and their assignments. However, it does not explicitly state when to prefer this tool over alternatives or provide any exclusion criteria. Still, for a zero-parameter list operation, the intended use is reasonably evident.

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