extract_contacts

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states that structured JSON is returned; it does not mention that the tool fetches the URL, potential latency, failure modes, or that it is non-mutating. This leaves a significant transparency gap.

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 two sentences long and front-loaded. The first sentence states the core purpose, and the second summarizes the output without unnecessary elaboration.

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 purpose and output shape are clear, and an output schema exists to document return values. However, the description omits usage guidance and the meaning of timeout_profile, so it is not fully complete for an agent to invoke the tool with confidence.

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. It implicitly clarifies that 'url' is the target URL, but it provides no explanation for 'timeout_profile', leaving the optional parameter completely ambiguous.

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 ('Extract all contact information from a URL') and names the concrete output fields (emails, phones, socials, detected names). This distinguishes it clearly from sibling tools like extract_links or scrape_url.

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 intended use is implied by the description: when you need contact information from a URL. However, it does not explicitly mention when not to use it or point to alternatives such as batch_contacts for multiple URLs, nor does it describe prerequisites like URL accessibility.

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