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

Annotations already mark readOnly/openWorld/idempotent, and the description adds substantial behavioral detail: identifiers are source-labelled, unresolved IDs are explicitly listed under `unresolved`, ambiguous FIGI matches return `figi_candidates`, and GLEIF/OpenFIGI enrichment degrades gracefully while EDGAR identifiers still return. It also discloses the internal multi-endpoint cascade, which is useful for latency expectations. There is no contradiction with the 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 front-loaded with query examples and an actionable 'Use FIRST' directive, and it is organized by supported types with parenthetical details. It is dense and somewhat overlong, with a few editorial asides ('which is the correct answer...') that could be trimmed, so while every sentence is informative it is not maximally concise.

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?

Despite having no output schema, the description tells the agent what will be returned: CIK, ticker, company_name, LEI, ownership fields, FIGI, RxCUI, ingredient, brand, citation, `figi_candidates`, and `unresolved`. It also covers edge cases including non-US ISINs, non-equity instruments, ambiguous names, and source outages, giving an agent enough context to call the tool and interpret results correctly.

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%, but the `value` parameter description adds critical semantics beyond the basic schema: accepted formats (ticker, CIK, ISIN, name; brand/generic for drug), a specific bond-issuer formatting warning, and an example contrasting issuer name vs full noun phrase. This tells the agent exactly how to construct valid input, not just what the field is called.

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?

States an explicit verb-resource pairing: 'resolve a user-spoken NAME to the canonical/official identifiers.' It enumerates supported entity types and concrete query paraphrases ('what's the ticker', 'find CIK', 'what's the LEI'), making the tool's scope unambiguous. It also positions itself as the first stop when a name needs an ID, distinguishing it from sibling tools like entity_profile or compare_entities.

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?

Gives a clear routing rule: 'Use FIRST whenever you have a name but need an ID' and explains that these identifiers are what other tools require as input. It does not name explicit alternatives or say when NOT to use it (e.g. when entity_profile is the better fit), so it stops short of full when/when-not guidance.

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