ENTIA Entity Verification

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

Annotations already provide readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds valuable context beyond annotations: it specifies the real-time nature of the check, the source (VIES database), and that the response is the official tax authority answer. This enhances understanding without contradicting 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 efficiently structured into four sentences, each adding distinct value: purpose, source, returns, and scope. There is no wasted text, and key information is front-loaded, making it easy to parse quickly.

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 tool's low complexity (1 parameter), high schema coverage (100%), presence of annotations, and an output schema (implied by 'Returns' statement), the description is complete. It covers purpose, source, return values, and scope adequately without needing to explain technical details already handled by structured fields.

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 input schema has 100% description coverage, with the parameter 'vat_id' fully documented. The description does not add any additional parameter semantics beyond what the schema provides, such as format examples or validation rules. Baseline score of 3 is appropriate since the schema handles the heavy lifting.

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 specific action ('Validate a European VAT number'), resource ('against VIES'), and scope ('Covers all 27 EU member states'). It distinguishes from sibling tools like entity_lookup or verify_dentist by focusing exclusively on EU VAT 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 description provides clear context for when to use this tool ('Validate a European VAT number'), but does not explicitly state when not to use it or name specific alternatives. It implies usage for EU VAT verification but lacks explicit exclusions or comparisons to similar tools.

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