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

Annotations already signal read-only/idempotent behavior, and the description adds rich behavioral context beyond that: cascading internal lookups, graceful degradation of LEI/FIGI enrichment, ambiguous-name behavior returning figi_candidates, explicit unresolved identifier reporting, and source-labeling of every identifier. No contradiction with annotations exists.

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 long, but the tool is genuinely complex and nearly every clause earns its place with caveats, examples, and behavioral notes. It is front-loaded with the general purpose and usage directive. The heavy use of nested parentheticals makes it slightly harder to scan, so it is not a perfect 5.

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?

For a tool with no output schema, the description thoroughly covers what is returned (CIK, ticker, LEI, FIGI, RxCUI, brand/ingredient, ownership links), when nothing is asserted (figi_candidates), how unresolved identifiers are represented, and how degraded enrichment behaves. An agent has enough context to call this correctly and interpret 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?

Although schema coverage is 100%, the description adds substantial meaning beyond the schema: it explains how company values map to ticker/CIK/name/ISIN, gives drug examples, and provides the critical instruction to pass only the entity name, not the full noun phrase, with the reason why. This materially improves correct invocation.

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 ('resolve') and resource ('user-spoken NAME to canonical/official identifiers') and states the tool's distinctive role: converting names to the identifiers other tools require. It clearly separates this from sibling tools with phrases like 'Use FIRST whenever you have a name but need an ID' and detailed type/variant examples.

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 trigger condition — 'Use FIRST whenever you have a name but need an ID' — and illustrates the lifecycle with many example phrasings. It does not explicitly name alternative sibling tools and say when NOT to use this one, so it falls just short of the strict 5-level standard.

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