lookup_bic

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

With no annotations provided, the description carries full burden. It discloses the data source (GLEIF entries), freshness (weekly refresh), and cost (0.003 USDC). It also lists return fields. However, it does not explicitly state that the operation is read-only or mention error handling for invalid BICs. Still, for a simple lookup, the disclosure is substantial.

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 relatively concise, with about 5 lines covering purpose, usage, data source, returns, and cost. It is well-structured with distinct sections. Some parts could be tightened (e.g., repeated examples), but overall it is efficient and front-loaded.

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 that an output schema exists, the description does not need to explain return values extensively, but it does list them. It includes data source freshness, cost, and differentiates from a key sibling. For a lookup tool with a single parameter, this is sufficient coverage.

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?

The input schema has one parameter with 100% coverage, describing BIC as an 8 or 11 alphanumeric string with examples. The description adds context but does not provide new parameter-level information beyond the schema. Baseline of 3 is appropriate as the schema carries the burden.

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 clearly states the tool resolves a BIC/SWIFT code into bank details (name, country, city, LEI, address). It uses a specific verb ('Resolve') and resource ('BIC / SWIFT code'). It distinguishes itself from the sibling 'validate_iban' by explicitly stating not to use for IBAN inputs, and provides distinct use cases.

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 includes explicit 'USE WHEN' and 'DO NOT USE' sections. It specifies when to use (user has a BIC/SWIFT and asks for bank details or LEI) and when not to use (IBAN inputs), and points to 'validate_iban' as the alternative. This provides clear contextual guidance for the agent.

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