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

With no annotations, the description carries full burden; it does disclose two meaningful behaviors: a no-charge refusal path when the required sources cannot be fetched, and a $1.00 USDC per-call x402 cost. It omits permissions, latency, and output shape. Useful but partial behavioral context.

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 coverage list is well front-loaded, but the refusal clause is stated twice in near-identical wording ('Refuses, with no charge, when ≥5 web sources + registry/EDGAR lookups cannot be fetched' vs 'Refuses, with no charge, when the required source...cannot be fetched'). That redundancy wastes space, though the overall length remains short.

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?

No output schema and no annotations, so the description must carry the load. It names the scanned categories and the payment/refusal mechanics, which is helpful, but never describes what a successful scan returns or its structure. Adequate for a one-parameter tool, but leaves the return-value picture undefined.

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?

Only one parameter ('task') with 100% schema description coverage, so the schema already documents it. The description adds no syntax, format, or content guidance for the task string beyond what the schema says. Baseline 3 is appropriate.

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+resource (automated due-diligence scan) and enumerates the coverage areas: financials, litigation, key personnel, IP, media sentiment, red flags. An agent can tell it is a broad DD scan rather than a single-source lookup like data.business-registry or data.sec-edgar-filing. It stops short of explicitly naming a sibling to contrast against, so it is clear but not maximally differentiated.

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 states refusal conditions and price but gives no guidance on when to choose this tool over the many adjacent siblings (data.business-registry, reputation.lookup, procurement.vendor-vetting, research.topic-deep-researcher). There is no when-to-use, when-not-to-use, or alternative routing. Implied only.

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