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

Annotations already mark the tool as read-only, open-world, idempotent, and non-destructive. The description adds substantial behavior beyond that: cascading through multiple lookup endpoints, graceful degradation when GLEIF/OpenFIGI are unavailable, returning figi_candidates and asserting nothing on ambiguous matches, labeling identifiers by provenance, and explicitly reporting unresolved identifiers. This is rich behavioral disclosure that no annotation could capture.

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 core usage guidance is front-loaded, but the company-type explanation is a dense, single block with nested parentheses and editorializing phrases like 'which is the correct answer to an issuer name that does not identify a single bond' and 'replaces 2-3 manual lookups.' The information is valuable, but bulleted or sectioned structure would make it much more scannable.

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 carries the full burden of explaining return behavior. It covers both entity types' output shapes, ambiguous-match behavior, unresolved identifiers, ISIN-to-legal-entity mapping, and enrichment outage degradation. For a complex tool with no output schema, this is exceptionally complete.

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 100%, but the description adds critical semantics: pass the entity name only, never the full noun phrase for bonds, and use the issuer exactly as printed. It also expands company input to ISIN, CIK, ticker, or name, and clarifies how type routes to different identifier systems. This goes well beyond the schema's brief 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 opens with a specific verb+resource pair: 'resolve a user-spoken NAME to the canonical/official identifiers other tools require as input.' It enumerates supported entity types (company, drug) and concrete outputs (CIK, ticker, LEI, FIGI, RxCUI), and the closing 'Use FIRST whenever you have a name but need an ID' positions it distinctly among siblings like lookup_name, entity_profile, and compare_entities.

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 tool gives an explicit trigger condition: 'Use FIRST whenever you have a name but need an ID,' and explains that it replaces 2-3 manual lookups. However, it does not name alternative tools or describe cases where a sibling such as lookup_name or entity_profile should be preferred, so it provides clear context but no explicit exclusions or alternatives.

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