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

Annotations already declare readOnly/openWorld/idempotent, and the description adds substantial behavioral depth beyond that: internal cascading through multiple lookup endpoints, graceful degradation when GLEIF or OpenFIGI is unavailable, behavior on ambiguous matches (returns `figi_candidates` and asserts nothing), explicit marking of unresolved identifiers under `unresolved`, and source labeling for every identifier. This gives the agent accurate expectations about edge cases and failure modes.

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 nearly every sentence earns its place given the tool's complexity (two entity types, multiple identifier systems, enrichment fallbacks). It is front-loaded with examples and the central 'Use FIRST' directive. A slight redundancy exists in repeating the cascade point and some over-explanation, but overall it remains well-organized and focused.

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?

The tool is complex—two types, multiple identifier sources, no output schema—yet the description covers input validation caveats, ambiguous-match behavior, unresolved-identifier reporting, and external-service degradation. An agent has everything needed to call it correctly and interpret results, especially given the rich annotations.

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 high-value meaning beyond the schema. For `value`, it warns to pass the entity name only, explains that trailing security-class words will match nothing in FIGI lookups, and gives a concrete bond-issuer example. For `type`, it details resolution behavior for each supported type. This is far beyond a baseline repetition of the schema.

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 concrete user queries and states a specific action: 'resolve a user-spoken NAME to the canonical/official identifiers other tools require as input.' It clearly distinguishes from siblings like entity_profile and compare_entities by positioning itself as the name-to-ID lookup, and even instructs 'Use FIRST whenever you have a name but need an ID.'

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?

Explicit usage guidance is front-loaded: 'Use FIRST whenever you have a name but need an ID,' reinforced by query examples across supported types. It clearly explains what input variants are accepted (ticker, CIK, ISIN, brand/generic name). It does not explicitly name alternative tools to use when an ID is already known, so it lacks a full when-not-to-use exclusion, but the context is otherwise clear.

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