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

Annotations only declare readOnlyHint and idempotentHint, so the description carries real extra weight: it discloses the pricing scheme (x402 v2, scheme upto, USDC on Base, max 30000 atomic) and the exact failure mode (PaymentRequired object with isError: true). It does not describe the success payload or whether a failed call is billed, which is the notable remaining 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?

Four short sentences, front-loaded with purpose, then payment terms, error behavior, and a coverage caveat — each sentence carries distinct information. It is dense with protocol jargon ("scheme upto", "DG-FG-PRICE-001") that costs tokens without helping an agent decide, but nothing is redundant.

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?

There is no output schema, so the description is the only place an agent could learn what a successful enrichment returns — and it only describes the failure path. Pricing, error semantics, and coverage limits are well covered, but the shape of the good-path response is entirely absent for a tool with no structured return contract.

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% and the single `domain` parameter is already documented with a format example in the schema. The description's phrase "by domain" only restates that, adding no constraints, normalization rules, or lookup-vs-input distinction beyond the schema.

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?

"Firmograph Public Plane company enrichment by domain" names a specific verb (enrichment), resource (company), and keying input (domain), which is enough for an agent to know exactly what the tool produces. There are no sibling tools to differentiate against, so the only gap is that "enrichment" leaves the returned field set unspecified.

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 gives strong operational gating: it is a paid tool, a call without a settled payment returns a PaymentRequired error, and settlement over MCP is not enabled in this version — effectively telling the agent when this call cannot succeed. It also flags a coverage limitation ("Not universal US SMB coverage"). What is missing is any positive guidance on when enrichment is the right choice versus other data sources, which is moot given there are no siblings.

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