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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds substantial value beyond those: it explains multi-endpoint cascading, graceful degradation when GLEIF/OpenFIGI are unavailable, explicit `unresolved` reporting, ambiguous-match handling via `figi_candidates`, ISIN-to-LEI mapping, and non-equity instrument coverage.

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 examples and the first-use rule, which is good. However, the body is one very dense paragraph with nested parentheticals and long asides; it would be more scannable as bullet points per entity type. Most sentences add value, but the structure makes it harder to parse quickly.

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 carries the burden of explaining return behavior, and it does: it mentions `figi_candidates`, `unresolved`, source-labelled identifiers, drug citations, and graceful degradation. It covers both supported types and edge cases well; a compact return-shape summary would make it fully 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 100%, but the description significantly extends parameter meaning: it gives ticker/CIK/name and brand/generic examples, explains ISIN behavior, and warns to pass the entity name only—especially the issuer exactly as printed for bonds. The "never the question's full noun phrase" clarification prevents a real class of invocation errors.

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 capability: resolving a user-spoken name to canonical/official identifiers required by other tools. It opens with concrete natural-language examples and closes with an explicit rule, "Use FIRST whenever you have a name but need an ID," which distinguishes it from sibling tools 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 gives clear usage context: use it first whenever an ID is needed but only a name is known, and it details supported types and accepted input forms. It does not explicitly name alternatives or state when not to use it relative to siblings, but the first-use guidance is strong enough to route an agent correctly.

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