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

Annotations already declare readOnly, openWorld, and idempotent hints, but the description goes well beyond them: it discloses graceful degradation when GLEIF/OpenFIGI are unavailable, internal cascading through multiple lookup endpoints, the behavior of returning figi_candidates instead of asserting on ambiguous matches, and the explicit listing of unresolved identifiers under `unresolved`. These are behavioral traits an agent cannot infer from annotations alone.

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 with concrete trigger examples and the "Use FIRST" directive, then organized under SUPPORTED TYPES. However, it is very long and contains long run-on parentheticals that reduce scannability; while nearly every detail is useful, tighter formatting or bulleted structure would improve readability without losing content.

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?

Given there is no output schema, the description carries the burden of explaining return behavior, and it does so thoroughly: it names the output fields (`figi_candidates`, `unresolved`, source labels), covers failure modes for non-equity instruments, and describes enrichment fallback. For a complex tool with two entity types and multiple upstream sources, the description is complete enough for an agent to call it correctly and understand what it will get 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?

Although the schema covers both parameters at 100%, the description adds substantial semantic value. It explains that `value` for a bond must be the issuer exactly as printed, warns against including trailing security-class words, and details how the same string can be a ticker, CIK, ISIN, or name. For `type`, it enumerates what each entity type returns and how enrichment works, far exceeding the schema's one-line 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 specific action — resolve a user-spoken name to canonical/official identifiers — and names the concrete resources it handles (CIK, ticker, LEI, RxCUI, FIGI). It distinguishes itself from sibling tools by framing itself as the first stop when you have a name but need an ID, and by listing supported entity types in detail. This leaves an agent with no ambiguity about what the tool is for.

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 invocation rule: "Use FIRST whenever you have a name but need an ID." It also explains that one call replaces 2-3 manual lookups, which helps the agent choose it over multi-step alternatives. However, it does not explicitly name sibling tools like entity_profile or compare_entities as alternatives or say when those should be used instead, so the exclusion guidance is incomplete.

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