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

Annotations already cover the safety profile (readOnly, openWorld, non-destructive), and the description adds genuinely new behavioral context: a $0.009 USDC per-call price, the x402 payment mechanism, accepted chains, and automatic payment for x402 clients. It does not mention rate limits or latency, but the payment disclosure is substantial value beyond the annotations.

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-loads the resource and returned fields, then the two access modes, then params, then payment/sample. Dense but efficient; the pricing and free-sample sentences are long but earn their place for an agent that must decide to pay.

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 compensates by listing the returned fields, and it documents the parameter union ('one required'), covering the main gaps. The main omission is differentiation from lookalike siblings (company_enrich, kyb_check), which an agent choosing between them would want.

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 75%, and the description adds the critical constraint that 'name or lei (one required)' — something the schema does not express (required parameters count is 0). It also restates country (ISO2) and limit (1–20, default 5), though those duplicate the schema's min/max/default.

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 ('Find companies worldwide in the Global LEI Index') and enumerates the returned fields (legal name, LEI, jurisdiction, register number, etc.), which distinguishes it from siblings like company_brief, company_enrich, and kyb_check. The two access modes (search vs. fetch) further pin down its scope.

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?

Explains the two usage modes clearly ('Search by name (optionally filtered by country) or fetch one LEI') so the agent knows how to invoke it in either case. However, it never names or contrasts an alternative sibling (e.g. company_enrich, kyb_check), so routing guidance is contextual rather than explicit.

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