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

The description goes far beyond the annotations, disclosing ambiguity handling ('returns figi_candidates to pick from'), an explicit unresolved-identifier behavior ('stated explicitly under unresolved rather than omitted'), source labelling, graceful degradation when GLEIF/OpenFIGI are unavailable, and internal cascading lookups. This gives an agent accurate expectations for uncertain and failure cases.

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 trigger phrases and a crisp 'Use FIRST' rule, and the main body is structurally organized by entity type. It is dense and long, with heavy parentheticals, but nearly every sentence carries a distinct piece of operational information rather than filler.

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?

Even without an output schema, the description covers what is returned per entity type, accepted inputs, ambiguity behavior, failure behavior, and degradation of enrichment sources. An agent has enough context to select this tool, format inputs, and anticipate the shape and caveats of the response.

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?

The input schema already documents both parameters with 100% coverage, and the description adds meaningful semantics beyond it: ISIN as an accepted company input, how ISIN resolves to a legal entity via GLEIF, and the bond-specific advice to pass only the issuer name. This materially helps an agent construct correct values for nonschema-documented cases.

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 names a specific action ('resolve a user-spoken NAME to the canonical/official identifiers') and clearly identifies the resource. It lists concrete trigger phrases like 'What's the ticker for…' and explicitly says 'Use FIRST whenever you have a name but need an ID,' which separates it from sibling tools that likely operate on already-resolved IDs or profiles.

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 an explicit trigger condition: use this first when a user has a name but needs an identifier, which is strong practical guidance. It also explains supported entity types and caveats like not passing the full noun phrase for bond lookups. However, it never names alternative tools or states exclusion cases, so it stops short of fully contrasting with siblings.

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