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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, but the description adds substantial extra behavioral context: on ambiguity it 'asserts nothing and returns `figi_candidates`'; unresolvable identifiers are 'stated explicitly under `unresolved` rather than omitted'; LEI/FIGI enrichment 'degrades gracefully' when GLEIF/OpenFIGI are down; and each call internally cascades through multiple lookup endpoints. No contradiction with annotations exists.

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 purpose and usage ('Use FIRST whenever you have a name but need an ID'), followed by clearly labeled sections for supported types and degradation behavior. It is dense and every sentence adds information, but the 'company' section is a long, heavily parenthesized run-on that would be more scannable as structured bullets.

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?

There is no output schema, so the description carries full responsibility for explaining return behavior — and it does: labelled source per identifier, `figi_candidates` for ambiguous matches, `unresolved` for failures, RxCUI with ingredient/brand and a citation link, plus LEI parent/ultimate-parent/children ownership. It covers edge cases (graceful degradation, non-US issuers, non-equity instruments) comprehensively for a two-type lookup tool.

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 well beyond the schema's enum and one-line parameter descriptions. It explains accepted input forms (ticker, CIK, ISIN, company name), details the ISIN-to-LEI mapping, distinguishes exact-ticker-map vs name-search behavior, and warns that for bonds the value must be the issuer exactly as printed, 'never the question's full noun phrase' because trailing security-class words match nothing.

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 verb+resource: 'resolve a user-spoken NAME to the canonical/official identifiers other tools require as input.' It enumerates two concrete entity types ('company', 'drug') with the exact identifier outputs (CIK, ticker, LEI, FIGI, RxCUI) and gives natural-language trigger examples ('What's the ticker for…', 'find the CIK for…'). It also distinguishes itself from siblings by explicitly framing itself as the name-to-ID layer that feeds 'other tools.'

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 an explicit trigger: 'Use FIRST whenever you have a name but need an ID.' It also explains when behavior diverges (ambiguous names return candidates, non-equity instruments still resolve, unresolved identifiers are surfaced). It does not name alternative sibling tools or state when-not-to-use it explicitly, so it falls just 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.