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

The annotations already declare read-only, open-world, idempotent, and non-destructive behavior, and the description adds substantial behavioral detail beyond that: LEI/FIGI enrichment degrades gracefully, ambiguous name matches return `figi_candidates` without asserting, unresolved identifiers appear explicitly under `unresolved`, and internal cascading occurs across several lookup endpoints.

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 organized and front-loaded with high-signal usage examples before the formal definition. Nearly every sentence adds operational value—supported types, fallback behavior, and input restrictions. It is more verbose than strictly necessary, but the density of useful guidance justifies most of the length.

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?

This is a complex multi-source, two-type tool with no output schema, and the description covers the critical call-time knowledge: accepted inputs, ambiguous-result behavior, explicit unresolved fields, graceful degradation when upstream services fail, and even non-US issuer coverage via ISIN-to-LEI mapping. An agent has what it needs to invoke the tool correctly in most situations.

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 significantly deepens parameter semantics. It documents that company input accepts ISINs beyond ticker/CIK/name, explains that non-equity instruments without tickers resolve here, and gives a precise usage rule for `value`: pass the entity name only, not the full noun phrase, because trailing security-class words will not match.

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 verb and resource: it 'resolve[s] a user-spoken NAME to the canonical/official identifiers other tools require as input.' It immediately distinguishes itself from other tools by saying to use it 'FIRST whenever you have a name but need an ID,' and the long list of example utterances makes the tool's role unmistakable.

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 clear, explicit usage context: 'Use FIRST whenever you have a name but need an ID' and explains that one call 'replaces 2-3 manual lookups.' It also details which input forms are accepted per type. However, it does not explicitly name sibling alternatives like entity_profile or state when NOT to use this tool.

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