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

With no annotations, the description carries the full burden and does reasonably well: discloses that access is free, that name lookups return only the top 3 matches (a result cap the agent must know about), and lists the fields returned even without an output schema. It omits error/no-match behavior and any rate or auth expectations.

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?

One sentence plus a leading 'FREE.' marker, front-loaded with the source system and the two modes. Every clause carries new information — cost, input formats, result cardinality, return fields.

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 two-param, no-annotation, no-output-schema tool, this covers inputs, cost, result cap, and returned fields — enough to invoke correctly. Missing only edge-case behavior (no matches, invalid LEI) and parameter precedence when both are passed.

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 description coverage is 0%, so the description must compensate, and it does: 'lei (20 chars)' gives a concrete format constraint, and 'name' is explained in terms of its output behavior (top 3 GLEIF matches with fields). It stops short of stating whether the two params are mutually exclusive or which wins if both are supplied.

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?

Names the specific resource (GLEIF LEI registration record) and the verb (lookup), and describes both operating modes — lookup by LEI vs. by company name. It doesn't explicitly contrast itself with siblings like entity_detail, but the LEI/GLEIF scope is distinctive enough for an agent to place it.

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?

States the two entry paths clearly: pass a 20-char LEI for a full record, or a company name for top 3 matches. That is actionable conditional guidance, though it says nothing about when to prefer this over entity_detail or sanctions_check.

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