vies_validate_vat_batch

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

With no annotations, the description carries the full burden. It usefully discloses that validation uses the official VIES API and that GDPR sole-trader personal data is automatically redacted, but it omits operational behavior such as authentication requirements, rate limits, failure handling, and response format.

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 a single, front-loaded sentence with no wasted words. It efficiently conveys the core action, data source, and two key behavioral traits.

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?

There are no annotations and no output schema, so the description must do more to make the tool fully usable. It leaves supplierCountryCode unexplained and does not describe the return value or error behavior, which are important for an agent invoking the 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?

Schema description coverage is 0%, so the description must compensate. It partially clarifies vatNumbers as 'one or more EU/XI VAT numbers', but it never explains the supplierCountryCode parameter or its default value.

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 states a specific verb and resource: batch validation of EU/XI VAT numbers against the official European Commission VIES REST API. It clearly distinguishes itself from sibling VIES tools such as vies_member_state_status and vies_licence_info by focusing on batch VAT-number validation.

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 mention of B2B reverse-charge eligibility implies a business use case, but the description does not explicitly say when to use this tool versus alternatives or when not to use it. Usage is inferable from the purpose but not fully guided.

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