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

Annotations already establish that this is a read-only, idempotent, non-destructive, closed-world operation. The description adds useful scope by saying it returns only verified phone numbers tied to SMS notifications and workflows, but it does not disclose pagination behavior, ordering, or default page size.

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 definition is a single front-loaded sentence with no wasted words. It communicates the resource and the relevant scope immediately.

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?

This is a simple list tool whose annotations already cover the safety profile. However, with no output schema and no parameter descriptions, the description would ideally mention pagination behavior or what a returned record contains, so it is adequate but not fully 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?

Schema description coverage is 0%, and the description does not mention the skip or take parameters at all. With two undocumented pagination parameters, the description fails to compensate for the schema's lack of parameter descriptions.

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 states a specific verb and resource: list the account's verified phone numbers. It also scopes the result to phone numbers used for SMS notifications and workflows, distinguishing it from siblings like get_verified_phone, list_verified_emails, request_phone_verification, and verify_phone.

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 by explaining that these are verified numbers used for SMS notifications and workflows, but it does not explicitly say when to choose this tool over get_verified_phone or when-not to use it. The context is clear enough to infer a listing use case, but no alternatives are named.

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