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

Even though annotations already mark the tool read-only, open-world, and idempotent, the description adds rich behavioral detail: graceful degradation of LEI/FIGI enrichment, explicit reporting of unresolved identifiers, returning figi_candidates instead of asserting a match, source-labelled identifiers, and ISIN-to-LEI mapping. These details materially change how an agent should interpret results and are not present in 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 dense and long, but almost every clause earns its place given the tool's dual entity types and multiple identifier systems. It front-loads the core purpose and usage instruction before diving into supported types. It loses a point for some overpacked parentheticals that reduce scannability.

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?

There is no output schema, so the description must carry the burden of explaining return behavior — and it does: labelled identifiers, unresolved lists, figi_candidates, ownership data, degradation paths, and per-type return fields. The tool is complex, yet an agent gets enough operational guidance to know what to expect and how to handle ambiguous or failed resolutions.

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 already 100%, but the description adds substantial meaning to the value parameter: accepted input forms (ticker, CIK, ISIN, name), the warning to pass only the entity name, the bond-issuer formatting guidance, and the note that trailing security-class words match nothing. This is exactly the kind of pragmatic disambiguation the raw schema could not provide.

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 verb and resource: resolve a user-spoken name into canonical/official identifiers required by other tools. It enumerates concrete entity types (company, drug) and the identifier systems involved, and the trigger phrases make it instantly recognizable. It is clearly distinguished from sibling tools like entity_profile by focusing on identifier resolution rather than profile enrichment.

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 explicitly says "Use FIRST whenever you have a name but need an ID," which gives a clear positive trigger condition. It does not explicitly name alternatives or state when not to use it, so an agent has to infer the boundary against siblings like entity_profile or search_within. The supported-type detail partially compensates by scoping acceptable inputs.

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