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

Annotations already mark the tool read-only/idempotent, and the description adds substantial behavior beyond that: it cascades across multiple lookup services, degrades gracefully when GLEIF/OpenFIGI are unavailable, returns figi_candidates instead of asserting on ambiguity, reports unresolved identifiers explicitly, and covers non-US/non-equity entities. None of this contradicts the 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 text is a dense wall of run-on parentheticals rather than a scannable description; the SUPPORTED TYPES section could be bulleted and the trigger examples shortened. Valuable details are buried in one enormous sentence, which reduces the description's usability for quick tool selection and parameter decision.

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?

Despite the lack of an output schema, the description tells the agent what will be returned (identifiers with source labels, unresolved list, figi_candidates), how failures degrade, and what input forms are accepted. For a two-parameter tool with this complexity, the coverage is thorough and would let an agent invoke it correctly in edge cases.

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 still adds meaning: it explains what each entity type resolves to (EDGAR spine, LEI ownership, FIGI, RxNorm citation), expands allowed inputs (ticker, CIK, ISIN, name), and warns about passing issuer-only names for bonds. This goes beyond the schema's short enum/value descriptions, though it also duplicates much of the schema.

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 opens with concrete natural-language triggers and states a clear verb+object: 'resolve a user-spoken NAME to the canonical/official identifiers other tools require as input.' It names supported entity types and output identifiers (CIK, ticker, LEI, FIGI, RxCUI), and this is distinct from sibling tools like entity_profile or compare_entities because it is explicitly about ID lookup/resolution.

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?

It provides explicit when-to-use guidance: 'Use FIRST whenever you have a name but need an ID' and supplies trigger phrasings. It does not, however, name alternatives or state when not to use it (e.g., when profile details rather than identifiers are needed), so it stops short of a full 5.

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