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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds real value beyond that: keyless access, CC0 open data, the exact return fields (with status and jurisdiction enums spelled out inline), and the ranked-candidate behavior of name search. No output schema exists, so enumerating returns is genuinely useful; only rate limits/pagination are unaddressed.

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-loaded with the core purpose, then inputs and usage context. The long return-field enumeration is dense but earns its place given there is no output schema. Slightly long, but no filler sentences.

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?

For a read-only, single-input lookup with no output schema, the description covers purpose, both input modes and their matching behavior, and the full return shape with inline enums. An agent has everything needed to call and interpret the result correctly.

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% (baseline 3), but the description adds meaning beyond the schema: it clarifies that the name path is a fuzzy match returning ranked candidates while the LEI path is exact. This disambiguates the two accepted input forms in a way the raw schema does not.

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 precise verb (resolve/look up) and resource (LEI) and names the data source (GLEIF public register). The dual mode — name-to-LEI or direct LEI lookup — plus the explicit field list makes it distinguishable from generic entity-resolution siblings like entity_resolve or resolve_entity.

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?

Gives clear context: use the LEI as a join key to disambiguate a company and cross-reference against sanctions, SEC EDGAR, federal spending, and due-diligence tools, and explains the name (fuzzy) vs LEI (exact) selection. It does not, however, explicitly name a sibling alternative or state when NOT to use this versus those tools.

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