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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint, so the safety profile is covered. The description adds valuable context: it extracts only from the company's own site, flags third-party/placeholder addresses instead of presenting them as valid, and discloses a per-call cost with payment method. This goes beyond minimal transparency.

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: the first front-loads the core functionality and unique value proposition, while the second provides cost and payment details. Every word contributes—no fluff or repetition. It is concise and well-structured.

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?

With no output schema, the description could have been expected to outline the return format more explicitly (e.g., fields returned, honesty flag). However, it states the extraction types (email, phone, social links) and implies the honesty flag. Combined with rich schema documentation and annotations, it is largely complete for a read-only extraction tool, but a brief mention of output structure would elevate 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 100%, so all four parameters (domains, checkPages, maxConcurrency, maxPagesPerDomain) are already well-documented in the schema. The description does not add additional parameter-specific meaning beyond the schema, but it does establish the overall purpose (extracting contacts) that gives context to the parameters. This meets the baseline.

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 the tool extracts public contacts (email, phone, social links) a company posted on its own site, with a specific verb ('Extract') and resource. It distinguishes itself from siblings like email-verifier by emphasizing the source (company's own site) and the honesty check for third-party/placeholder addresses.

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 when to use this tool (to obtain contacts from a company's official website) and highlights a unique honesty-check feature that differentiates it from simple scrapers. However, it does not explicitly mention alternatives or state when not to use it, leaving some room for ambiguity.

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