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

With no annotations, the description carries the full burden and does solid work: it discloses the $0.01 USDC cost, that it returns x402 payment requirements, and that the agent's wallet must execute the payment. It does not cover failure modes such as whether the fee is still charged when no lead is found, which keeps it short of a 5.

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?

Front-loaded with purpose, then cost, payment mechanics, and examples in four tight clauses with no filler. Slightly more text than strictly necessary, but every sentence carries actionable information.

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?

An output schema exists, so return-value explanation is not required; the description instead covers the non-obvious paid-invocation flow, which is the highest-value context for this tool. The only gap is behavior on a no-match or failed payment.

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 0% and 'query' has no schema description, so the description must compensate — and it does by giving accepted input forms via examples ('Acme Corp' as a company name, 'acme.com' as a domain). It does not clarify precedence when a string could be read as either, so it is not a full 5.

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 ('B2B lead enrichment: contact lookup by company name or domain') and names the exact deliverable ('verified business email + source URL'). An agent immediately knows what the tool produces and what input it consumes, which is enough to distinguish it from the unrelated buy_pack/list_packs siblings.

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 implied rather than stated: 'Enrich one lead' signals single-record scope (as opposed to bulk), but there is no explicit when-to-use, when-not-to-use, or named alternative. It never says what to do if no email is found or whether to prefer another tool for batch enrichment.

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