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

Beyond the annotations (readOnly, openWorld, idempotent, non-destructive), the description discloses significant runtime behavior: internal cascading of multiple lookup endpoints, graceful degradation when GLEIF/OpenFIGI are unavailable, explicit `unresolved` output for failed identifiers, and ambiguity handling via `figi_candidates`. It also clarifies a non-obvious behavior: non-equity instruments without tickers still resolve, and issuer names that do not identify a single bond are intentionally left unresolved.

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 very long and dense, with many semicolon-connected clauses that can be hard to scan. However, nearly every clause carries distinct, useful information rather than padding, and the opening example phrasings effectively front-load the tool's purpose. A more structured layout would improve scannability, but the length is largely justified by the tool's broad behavior.

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 is thorough about what the agent should expect: identifier names, source labels, unresolved entries, ambiguity results, and enrichment-failure behavior. It covers both entity types, input conversion paths such as ISIN-to-LEI, and the intended place of the tool in a multi-step workflow. Nothing essential for selecting or invoking the tool correctly appears to be missing.

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 description coverage is 100%, the description adds crucial semantics beyond the schema: for `value` it explains acceptable formats per type, warns to pass the entity name only, and gives a concrete bond-issuer pitfall with trailing security-class words. For `type` it explains exactly what each enum value returns and which upstream sources establish each identifier. This materially improves correct invocation.

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 precise verb+resource: it resolves user-spoken names into canonical/official identifiers required by other tools, and enumerates supported types ('company', 'drug'). It also makes the scope unmistakable through examples like "find the CIK for" and "what's the LEI for." It differentiates itself as the first-step name-to-ID tool, even though it does not name sibling alternatives explicitly.

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?

It gives clear, directive usage guidance: "Use FIRST whenever you have a name but need an ID." This tells an agent when to invoke the tool, and examples of query phrasings reinforce the trigger conditions. It does not explicitly state when not to use it or name alternative tools, so it stops 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.