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

Annotations already convey read-only, idempotent, open-world, and non-destructive, but the description adds substantial new behavioral context: graceful degradation ('if GLEIF or OpenFIGI is unavailable, the EDGAR identifiers still return'), ambiguity handling (asserts nothing and returns figi_candidates), explicit unresolved reporting, source labeling of every identifier, and internal cascading 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 well front-loaded with example queries and the core purpose, but the company-type explanation is a single sprawling parenthetical packing several behaviors (FIGI matching, ambiguity, ISIN mapping, degradation) into one dense block. It is thorough and nearly every sentence earns its place, but the wall-of-text structure hurts agent scannability.

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 complex two-type tool with no output schema, the description explains return identifiers (CIK, ticker, LEI, FIGI, RxCUI), data sources, ambiguity outcomes, and failure modes. The main gap is a clean statement of the response object's shape; mentions of figi_candidates and unresolved partially cover this but a structured return description 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%, so baseline is 3, but the description adds critical value-param semantics: the 'ENTITY NAME ONLY' rule with a concrete bond example ('NEW YORK ST DORM AUTH' vs trailing security-class words matching nothing) and the accepted input forms (ticker, CIK, ISIN, name). The type param is also enriched by explaining exactly what each type returns.

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 example queries ('What's the ticker for…', 'find the CIK for…') and states the core function: 'resolve a user-spoken NAME to the canonical/official identifiers other tools require as input.' This is a specific verb+resource that also distinguishes it from siblings like entity_profile and compare_entities by positioning it as the identity-resolution prerequisite.

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?

'Use FIRST whenever you have a name but need an ID' is an explicit trigger condition, reinforced by the example-query list and the efficiency note that it 'replaces 2-3 manual lookups.' It does not explicitly name alternatives or state when-not-to-use cases, so it stops short of a 5.

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