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

Beyond the annotations (readOnly/openWorld/idempotent/non-destructive), the description discloses behavior that materially affects call outcomes: internal cascading across multiple lookup endpoints, graceful degradation when GLEIF/OpenFIGI are unavailable (EDGAR identifiers still return), asserting nothing and returning `figi_candidates` on ambiguous matches, and stating unresolved identifiers explicitly under `unresolved` rather than omitting them. These fallback and ambiguity behaviors are exactly the context annotations cannot convey.

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 front-loads well with trigger phrases and a one-line usage directive, and every sentence carries real information. However, the company-type section is a run-on with deeply nested parentheticals that is difficult to scan; restructuring into bullets or separate sentences would materially improve readability.

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 multi-source tool with no output schema, the description is remarkably complete: it covers accepted inputs, produced identifiers, source labelling, the `unresolved` and `figi_candidates` fields, non-US issuer coverage via ISIN, and graceful degradation. The only notable gap is that the overall return shape is never formally described, which matters more here given the absence of an output schema.

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 the baseline is 3, but the description adds meaning the schema lacks: company input also accepts ISIN (the schema's value description only lists ticker, CIK, and name), and value semantics for bonds require the issuer exactly as printed, never the full noun phrase. The ISIN-to-LEI resolution path and the drug-type RxCUI/ingredient/brand output mapping further enrich parameter understanding beyond 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 states a specific action — resolving a user-spoken NAME to canonical/official identifiers that other tools require as input — and enumerates the supported types (company, drug) and the identifiers produced (CIK, ticker, LEI, FIGI, RxCUI). The trigger-phrase examples ("What's the ticker for…", "find the CIK for…") make the purpose unmistakable and distinguish it from siblings like entity_profile or compare_entities, which consume IDs rather than produce them.

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 explicit when-to-use guidance: "Use FIRST whenever you have a name but need an ID," reinforced by a list of trigger phrasings and per-type accepted input forms (ticker/CIK/ISIN/name for company; brand/generic for drug). It stops short of naming sibling alternatives or explicit when-not-to-use conditions, so it earns a 4 rather than a 5.

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