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

Annotations declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true, which align with the description's validation-only nature. The description adds input formatting details (spaces allowed, auto-stripped) and mentions 'detailed breakdown' as output, but could further disclose potential limitations like country-specific validation rules.

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?

Two succinct sentences cover purpose, output details, and scope. Every word adds value; no redundancy or fluff.

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 output schema exists (not shown but referenced), the description adequately covers input format, output content, and geographic scope. For a simple validation tool, this is fully complete.

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 sole parameter 'iban' is fully documented in the schema (100% coverage). The description adds valuable semantics beyond the schema by noting that spaces are allowed and auto-stripped, clarifying input flexibility.

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 validates IBANs and retrieves associated bank info (BIC/SWIFT, bank name, address, country, currency, SEPA membership), with explicit scope of 80+ countries. It distinguishes from sibling tools like 'iban.banking.calculate' by its specific validation and info retrieval purpose.

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 does not explicitly mention when to use this tool versus alternatives or provide exclusion criteria. While the purpose is clear, there is no guidance on when not to use it (e.g., for generating IBANs, use 'iban.banking.calculate').

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