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

Beyond the readOnly/idempotent/destructive annotations, the description discloses graceful degradation when GLEIF/OpenFIGI is unavailable, internal cascading through multiple lookup endpoints, explicit `unresolved` reporting instead of silent omission, and ambiguous-match behavior returning `figi_candidates`. This is rich behavioral context the annotations alone do not provide.

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 front-loaded with common user phrasings and a clear directive, and every clause carries useful information. It is long and dense, with large parentheticals, but the complexity of the tool justifies most of the length; a little more structuring would make it easier to scan.

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?

Given the tool's complexity, two entity types, and multiple backing sources, the description covers edge cases such as ambiguous bonds, non-US issuers, unresolved identifiers, and degraded enrichment. Even without an output schema, it tells the agent what to expect in ambiguous and failure cases, making it complete enough to invoke correctly.

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 the schema already describes both parameters, the description adds critical semantic guidance: accepted input formats like ticker versus CIK versus ISIN, brand versus generic drug names, and a concrete warning to pass only the entity name for bonds, with an example showing why trailing security-class words fail. 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 states a specific verb and resource: resolve a user-spoken name to the canonical/official identifiers other tools require. It also distinguishes itself from siblings by positioning it as the first step whenever a name needs to become an ID, and by listing the two supported entity types with their exact identifier outputs.

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 explicit usage direction with 'Use FIRST whenever you have a name but need an ID' and explains what inputs it accepts. It does not explicitly name alternative tools to avoid, but the clear context and priority instruction are strong enough for an agent to select it correctly.

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