extract_phones

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

With no annotations provided, the description carries the burden of disclosure. It does disclose the output shape (`results` with url/value/context and `errors`), which is helpful behavior transparency. However, it does not mention operational traits such as network requests, rendering, or failure modes beyond the presence of an errors array.

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 concise sentences, front-loaded with the action. Every word contributes meaning, and the return format is summarized compactly.

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?

The tool has two input parameters, one of which (`js_render`) is completely unexplained, and no annotations are present. Although an output schema exists, the description's silence on rendering behavior, request scope, and edge cases leaves important gaps for an AI agent deciding whether to use the tool and how to configure it.

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%, so the description must compensate for parameter meaning. It partially covers `urls` by saying 'list of URLs', but it says nothing about `js_render`, an optional boolean parameter that likely controls JavaScript rendering. The description adds minimal value beyond the 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 clearly states a specific action ('Scan a list of URLs') and a specific target ('for phone numbers'). It also distinguishes the tool from sibling tools like extract_emails, extract_links, and extract_social_links by explicitly naming the data type being extracted.

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 the tool is used when you have a list of URLs and need to find phone numbers, but it provides no explicit when-to-use, when-not-to-use, or alternative tool guidance. Context is clear but not elaborated.

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