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

No annotations are provided, so the description carries the full behavioral burden. It discloses the external source (GLEIF registry) and the returned fields, which is helpful, but says nothing about read-only semantics, rate limits, auth needs, or not-found behavior.

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?

Three tight sentences, front-loaded with the verb+resource and then the return fields. Efficient, though the final value-statement sentence is somewhat promotional.

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 steps in to name the returned fields (LEI code, status, address), which is what an agent needs. Minor gaps around failure modes and result limits, but adequate for a two-param read lookup.

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%, so both parameters are already documented in the schema. The description only restates the lookup key ('by legal name') and adds no extra meaning for legalNames or matchesPerName, making the baseline 3 correct.

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 (look up) and resource (LEI in the official GLEIF registry) plus the lookup key (legal name). It is clearly distinguishable from siblings like resolve_company_identity or search_companies_house_uk, which target different registries.

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 line 'The authoritative source for checking that a company legally exists' gives an implied use case, but there is no explicit when-not guidance and no routing to alternatives such as resolve_company_identity. Usage is inferable rather than stated.

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