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

The annotations already declare read-only, idempotent, open-world behavior. The description adds substantial behavioral context beyond those hints: internal cascading lookups replace 2-3 manual calls, identifiers are labeled by source, unresolved identifiers are explicitly listed, ambiguous matches return figi_candidates, and LEI/FIGI enrichment degrades gracefully when external sources are unavailable. No contradiction with 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 densely packed and somewhat run-on, with large parentheticals that reduce scannability. However, each clause contributes useful information—supported identifiers, ambiguity behavior, graceful degradation—rather than filler. It is front-loaded with trigger phrases and the core purpose before expanding into detail.

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 the absence of an output schema, the description covers what is returned: canonical identifiers, source labels, unresolved fields, figi_candidates on ambiguity, and RxCUI citations. It also explains fallback behavior if GLEIF/OpenFIGI are down. For a tool of this complexity, an agent has enough information to call it appropriately and interpret its results.

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 complete, but the description goes far beyond it: it documents ISIN as a valid company input, shows examples for each type, and warns about passing only the issuer name without trailing security-class words. It also clarifies that a non-ticker instrument can still resolve via name search, which meaningfully enriches the schema's bare parameter 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 states a precise verb-object pair: resolve a user-spoken name into canonical/official identifiers that other tools require. It enumerates supported types and concrete identifier examples (CIK, LEI, RxCUI, FIGI), and its 'Use FIRST whenever you have a name but need an ID' distinguishes it from downstream 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 strong when-to-use signals: explicit natural-language triggers and a direct 'Use FIRST' directive. It does not name an alternative tool explicitly or give a corresponding 'do not use if...' exclusion, but the context of being the pre-step to other tools requiring IDs is clear.

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