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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds valuable behavioral context: it is backed by 121,000+ entries, monthly refreshes, LEI enrichment sources, and cost details, which helps the agent set expectations about coverage and pricing without contradicting the 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 well-organized with clear labeled sections (main purpose, USE WHEN, DO NOT USE, BACKED BY, COST). Every section earns its place, and the core functional statement is 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?

With a single required parameter, a complete schema, an output schema, and a description that covers input format, use cases, exclusions, data coverage, and cost, nothing important is missing for an agent to select and invoke this tool 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?

The schema describes 'bic' as 'BIC/SWIFT code (8 or 11 chars)', and the description goes further by adding 'alphanumeric' and concrete examples like 'UBSWCHZH80A' and 'DEUTDEFF'. This reduces ambiguity and reinforces the expected input format beyond the schema baseline.

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?

States a specific verb ('Resolve') with a well-defined resource (BIC/SWIFT code) and concrete outputs (bank name, country, city, LEI, address). It also distinguishes itself from sibling validate_iban by explicitly saying what it is not for, which makes the tool's scope 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?

The description gives explicit USE WHEN conditions (user already has an 8 or 11 char BIC/SWIFT and asks which bank/LEI) and a clear DO NOT USE exclusion (IBAN inputs) with a named alternative (validate_iban). This is ideal routing guidance for an AI agent.

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