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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful non-schema context: cost ($0.80 USDC per call on Base), the x402 payment mechanism, and the no-charge-on-failure guarantee, which an agent needs before invoking a paid tool.

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?

Two tight sentences, zero filler, with the capability stated first and the billing terms second. Nothing is wasted or buried.

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 carries the burden of indicating what enrichment data comes back, and it says nothing about returned fields, structure, or per-domain error behavior. Billing and scope are complete, but the return-value side is left blank for a read tool.

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?

With one parameter at 100% schema coverage (including maxItems: 10), the schema does the documentation work. The description's 'up to 10 domains' merely restates the schema bound and adds no format hints (e.g., whether bare domains or URLs are expected).

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 ('Company enrichment for up to 10 domains'), which is clear and actionable. It implicitly separates itself from the single-domain sibling company_enrich via the batch framing, but never names that alternative 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?

The 'up to 10 domains' cap implies this is the multi-domain path, so usage is reasonably deducible. However, it gives no explicit guidance on when to choose this over company_enrich or the batch scoring siblings, and no prerequisites or exclusions.

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