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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds substantial behavioral context beyond those annotations: it cascades through multiple lookup endpoints, returns `figi_candidates` on ambiguous matches, reports unresolved identifiers explicitly under `unresolved`, and degrades gracefully when GLEIF/OpenFIGI are unavailable. This is rich, non-redundant transparency.

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 dense but front-loaded: it opens with concrete user queries and the 'Use FIRST' guidance before diving into type-specific details. The prose is long and somewhat sprawling with many parentheticals, but most clauses carry real decision-relevant content, so it earns its length for a tool with this complexity.

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?

With no output schema, the description carries the burden of explaining what the tool returns, and it does so thoroughly: it names the identifiers returned per type, the `unresolved` field, the `figi_candidates` ambiguity case, and the graceful-degradation behavior. An agent has enough information to decide when to call it and what to expect back.

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, and the schema already documents `type` and `value` thoroughly. The description adds semantic meaning beyond the schema by noting that ISINs are accepted for company resolution, that an ISIN resolves to the issuing legal entity via GLEIF, and that drug lookup accepts both brand and generic names. This meaningfully exceeds the schema but still leaves some parameter behavior articulated in the schema rather than the description.

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 the tool's job: resolving a user-spoken name into canonical/official identifiers like CIK, LEI, FIGI, and RxCUI that other tools require. It goes beyond the title by enumerating supported entity types and example queries, but it does not explicitly contrast itself with sibling tools such as entity_profile or compare_entities, stopping short of full sibling differentiation.

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 selection rule: 'Use FIRST whenever you have a name but need an ID,' reinforced by example user phrasings. It establishes clear context for when this tool is appropriate, but it does not state exclusions or name alternative tools to choose instead, so the guidance is strong but not exhaustive.

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