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

Beyond the readOnly/idempotent annotations, the description discloses rich behavioral detail: ambiguous instruments return figi_candidates, unresolved identifiers appear under unresolved rather than being omitted, enrichment degrades gracefully, and ISINs resolve through GLEIF to the legal issuer. This substantially exceeds what annotations alone 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 is long, rambling, and contains a grammatically broken sentence ("more than one instrument it asserts nothing") that obscures the meaning. Useful details are buried inside parenthetical tangents, and the 'cascades through several lookup endpoints' point is effectively repeated. It is not appropriately sized or cleanly structured.

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 tool with no output schema, the description covers return contents (CIK, ticker, company_name, LEI, ownership, FIGI candidates, RxCUI + ingredient + brand), failure behavior, graceful degradation, and cross-entity handling. An agent has enough context to invoke it correctly and interpret results, despite the prose quality.

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?

Although schema coverage is 100%, the description adds significant practical meaning: accepted value formats for company vs drug, ISIN as an additional accepted input, and a concrete failure-mode warning about passing only the issuer name rather than the full noun phrase. This goes well beyond the schema's brief descriptions.

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 clearly states that the tool resolves a user-spoken NAME into canonical/official identifiers, naming concrete examples (ticker, CIK, LEI, RxCUI) and framing it as the required first step before other tools. It distinguishes itself from sibling lookup tools by positioning this as the identity-resolution entry point.

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 usage rule: "Use FIRST whenever you have a name but need an ID." It also explains that the tool replaces 2-3 manual lookups, but it does not explicitly name sibling tools to avoid or when to prefer them instead.

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