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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing cost ($2 USDC per call via x402), conditional non-billing when sources are insufficient, the async pre-check-before-queue-and-charge behavior, the company-level-only data scope (no personal emails), and the 20-company cap. These are exactly the operational facts an agent needs before spending money.

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?

Purpose is front-loaded in the first clause, followed by output scope, limits, and billing in descending order of importance. The opening sentence is dense and clause-stacked, but nearly every clause carries distinct information rather than filler.

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 carries the return-value burden and does it well — what they do, location, fit score and reason, contact page, role-based emails, socials, and a PDF link. Cost and async behavior are covered. Minor gaps remain around latency, failure modes, and what happens to the PDF link after 7 days.

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 coverage is 67% and the description usefully reinforces it: 'up to 20 companies' clarifies the count ceiling, 'plus a PDF' clarifies the pdf flag, and the async billing note explains the async flag beyond its one-line schema text. location and webhook_url remain slightly thin, but the description compensates more than it repeats.

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?

States a specific verb and resource — a B2B lead list built from a plain-English ideal-customer description — and describes the actual pipeline (web search, per-site profiling, match filtering). An agent can distinguish it from report_company or uk_companies_search by the inputs and outputs described, though it never names a sibling explicitly.

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?

Gives clear usage context: supply a plain-English customer description, receive up to 20 companies, and choose async/webhook for long jobs. Billing conditions ('you are not charged if too few sources answer') and the x402 cost tell the agent when the call is worth making. No explicit when-not-to-use or named alternative is provided.

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