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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals the output fields, real-time nature, worldwide coverage, and pricing/payment details ($0.01 per call via x402). It does not mention failure modes or status codes, but for a lookup tool the disclosed context is substantial.

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 description is two sentences, front-loaded with purpose, then returns and pricing. Every clause adds value—no filler or redundancy.

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?

Despite lacking an output schema, the description enumerates the key return fields (legal name, status, jurisdiction, legal form, registered address) and adds real-time/coverage/price context. For a single-parameter lookup, this is sufficient for an agent to understand expected behavior.

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 100% with the 'lei' parameter already described (20-character format and example). The tool description adds no extra parameter-level nuance beyond restating that it looks up an LEI, so it meets the baseline without exceeding it.

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?

The description clearly states the verb ('Look up') and the specific resource ('Legal Entity Identifier (LEI)') against the official GLEIF registry. It lists the returned fields (legal name, status, jurisdiction, etc.) and explicitly positions it for KYB/company lookup, which distinguishes it from siblings focused on crypto/trading/sanctions.

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 provides a clear context for use: 'for company information lookup and counterparty / know-your-business (KYB) identity.' It does not explicitly name alternatives or exclusions, but the sibling tools are thematically different, making the intended use unambiguous.

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