parse_phone_number

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

With no annotations, the description carries the full burden. It discloses the cost ($0.001 USDC via x402), which is useful, but it does not disclose input format expectations, output structure, error behavior, supported phone formats, or limitations.

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 very short and front-loaded. However, the first sentence merely restates the tool name, and the 'Other Utilities tool' label is of limited value. The cost detail is relevant and earns its place. It is concise but not maximally information-dense.

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 degenerate parameter schema and lack of output schema, the description is insufficient for an agent to know what input to provide or what result to expect. The cost detail does not compensate for missing behavioral and parameter context.

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 input schema only contains a generic 'params' object with no internal property definitions, and the description adds no parameter details beyond the tool name. The schema description coverage is technically 100% but vacuous, as it only says 'Tool parameters as JSON object'. The description doesn't compensate for the lack of meaningful parameter guidance.

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 'parse phone number', which is a specific verb+resource. It is clear what the tool does at a basic level, but it doesn't add any detail about the scope or behavior of parsing. No sibling tool is a phone parser, so it is somewhat distinguished by default, but the description itself doesn't explicitly differentiate it.

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 guidance is provided on when to use this tool, what alternatives exist, or any exclusions. The only additional note is the cost, which relates to payment, not usage context.

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