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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the key behavioral traits: single-page scope with no crawling, output limited to what the page visibly publishes, and the pricing model ($0.002 USDC per successful call via x402 on Base/Solana/Arc) with failed calls not charged. The billing detail is critical and cannot be inferred from any structured field.

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 core capability and its scope (one page, https, no crawl) are front-loaded in the first sentence, with cost and billing caveats following. Every clause carries operative information: included link types, the anti-crawl constraint, and the payment terms.

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 one-parameter open-world read tool, the description covers scope, constraints, output contents, and cost. Because an output schema exists, no return-value schema detail is required, and the payment/failure semantics round out everything an agent needs before calling 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?

With a single required parameter at 100% schema coverage, the schema already carries the baseline documentation. The description still reinforces the semantics that matter — the URL must be public and https, and only one page is read — which adds slight value beyond the schema's 'max 300 characters' note.

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 names a specific verb (extract/read) and resource (contact details from a single public web page), and enumerates exactly what is returned: mailto/tel links, in-text email addresses, social profile links, and the page title. This is far more specific than the generic 'Social Contact Info' title and lets an agent distinguish it from platform-specific contact tools in the sibling list.

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?

Usage context is clear: supply one public https URL, single page only, no crawling, nothing returned that the page doesn't already show. The https-only and single-page constraints implicitly steer the agent away from crawl-style or bulk tools, but it never explicitly names an alternative such as the platform-specific contact-info siblings (e.g. social_facebook_page_contact_info, social_instagram_contact).

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