iban_validate

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds two genuinely useful facts beyond them: it calls an external provider (OpenIBAN) and it returns bank/BIC metadata rather than a bare boolean. It stops short of saying what happens on an invalid IBAN (error vs. valid=false).

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?

A single front-loaded sentence naming the action, the input, the enrichment, and the provider. Nothing redundant.

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 one-parameter read tool with full annotations, this covers intent and output substance. There is no output schema, so a brief note on the shape of the bank/BIC payload or on invalid-IBAN behavior would have closed the last gap.

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?

One required parameter at 100% schema coverage, so the schema already fully documents the input. The description adds nothing about IBAN formatting expectations, which would have been the one place it could have compensated.

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 ('Validate') and resource ('IBAN') plus the secondary payoff (bank/BIC info) and the underlying provider (OpenIBAN). No sibling tool does IBAN validation, so differentiation is not required, but the description doesn't need to name alternatives.

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?

Usage is only implied by the verb 'Validate' — there is no statement of when to reach for this versus doing ad-hoc format checks, nor any note about what input forms are acceptable (spacing, country prefix, length). No exclusions or alternatives are given.

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