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

No annotations are provided, so the description carries full burden. It discloses that the LEI is checksum-validated first, that the tool costs money, and that an API key with a funded balance is required. This is good disclosure of the financial and validation behavior, though it does not specify what happens if validation fails or in what format the record is returned.

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 that front-load the main purpose and then add critical constraints (cost, authentication). Every word earns its place; no fluff 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?

Given there is no output schema, the description lists the expected output fields which helps agents know what to expect. The tool has a side effect (cost) and authentication requirements, which are explicitly covered. The absence of error handling or failure behavior details is a minor gap, but for a lookup tool with clear inputs and outputs, the description is adequately complete.

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 50%, meaning the API key parameter is not described in the schema properties but is documented in the description. The description explains the LEI role, adds checksum validation, and details the api_key requirement including how to fund it and alternatives via x402. This goes beyond what the schema provides for the api_key, though it leaves the LEI parameter without format details beyond the schema (maxLength/minLength).

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 tool resolves an LEI to its official GLEIF record with specific fields (legal name, status, jurisdiction, country, registration status). This distinguishes it from siblings like search_lei_by_name (which likely searches by name) and validate_identifier (which likely only validates format), while the note on checksum validation adds specificity.

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 implies use when you have an LEI and need its official record, but it does not explicitly state when to prefer this over validate_identifier or search_lei_by_name. It mentions the cost and authentication prerequisites, which are important context but not alternative tool guidance. The paid nature suggests a cost-benefit consideration that is not fully spelled out.

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