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

Annotations already indicate read-only, idempotent, open-world behavior, and the description goes well beyond by disclosing graceful degradation when GLEIF/OpenFIGI are unavailable, explicit `unresolved` fields, `figi_candidates` returned on ambiguous matches, per-source identifier labeling, and the internal cascade of lookups. No contradiction with annotations.

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 front-loaded with user-phrase examples and the crisp 'Use FIRST' directive, and the long body is dense with useful behavior. It is somewhat verbose and repeats some information already present in the schema, so it does not earn a perfect conciseness score, but it is appropriately sized for the tool's complexity.

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?

This is a complex multi-endpoint tool with no output schema, and the description covers return expectations (`figi_candidates`, `unresolved`, source labels), failure/degradation behavior, input formats, and type-specific edge cases. Everything an agent needs to decide when to call it and how to pass parameters correctly is present.

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%, but the description adds substantial semantic guidance: pass the ENTITY NAME ONLY, use the issuer exactly as printed for bonds, never include trailing security-class words, and accept ticker/CIK/ISIN/name for companies versus brand/generic names for drugs. These details materially prevent incorrect invocation.

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 states a specific action — resolving a user-spoken name to canonical/official identifiers — and names the supported entity types (company, drug) with their concrete outputs. It also frames the tool as the first step when a name needs to become an ID required by other tools, which distinguishes it from sibling lookups like entity_profile or compare_entities.

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 explicitly says 'Use FIRST whenever you have a name but need an ID' and gives examples of when this is appropriate, including bond issuers and ISIN lookups. However, it does not explicitly name sibling alternatives or state when not to use this tool, so it stops short of full exclusion guidance.

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