Lookup BIC/SWIFT

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

Annotations already indicate read-only, idempotent, non-destructive behavior, so the bar for additional context is met by the description's specifics: 121k+ BIC entries, 38k+ LEI-enriched via GLEIF, monthly refresh, and 0.003 USDC cost. It also says fields are returned 'if available', setting expectations about completeness. No contradiction with annotations.

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 compact despite covering purpose, usage, exclusions, data provenance, return fields, and cost. Information is front-loaded in a scannable label format. Each sentence contributes actionable meaning, and there is no filler or redundancy.

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 single-parameter lookup tool with strong annotations and an output schema, the description is fully sufficient. It explains when to use, when not to use, what data backs the tool, what will be returned, and the cost. Nothing an agent needs to decide correctly is missing.

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 description coverage is 100%, and the schema already documents the BIC parameter with format and examples. The description repeats the same examples and 8/11-character format without adding new parameter-level meaning. It does clarify the output mapping, but the parameter itself is already well-defined in the schema, so a baseline 3 is appropriate.

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 a specific verb and resource: 'Resolve a BIC / SWIFT code into the underlying bank: name, country, city, LEI, address.' It clearly differentiates from sibling validate_iban by explicitly saying not to use it for IBAN inputs. This leaves little ambiguity about what the tool does and how it differs from related tools.

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 'USE WHEN' section gives concrete triggers: the user already has a BIC/SWIFT and asks which bank it belongs to, location, or LEI for compliance. 'DO NOT USE for IBAN inputs — call validate_iban instead' provides an explicit exclusion and names the alternative. This is exemplary usage guidance.

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