validate_eori

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states only the purpose ('Validate') without revealing how validation works, whether it consults external systems, what happens on invalid input, or what the response structure contains. This is a significant gap for a tool that likely performs network-backed checks.

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, compact sentence that front-loads the core purpose and provides contextual variation. There is no wasted wording, and it communicates the essential function immediately.

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?

The tool is simple with one parameter, but the absence of annotations and low param coverage leaves important aspects unaddressed—e.g., whether validation is synchronous, if there are rate limits, or error behavior. The presence of an output schema mitigates return-value explanation, but overall the definition is only minimally complete for a validation tool.

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 provides no description for the eori_number parameter, and schema coverage is 0%, so the description must compensate. It mentions the authorities but does not explain the expected format (e.g., country prefix + digits, length, examples). The parameter meaning is self-evident from the name, but the description adds no syntax or validation rules beyond that.

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 an EORI customs number, a specific resource type, and it names the relevant authorities (EU via EC, GB via HMRC, XI for Northern Ireland). This distinguishes it from sibling validation tools like validate_vat or validate_iban, which handle different identifier types.

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?

There is no explicit guidance on when to use this tool versus alternatives. It does not mention prerequisites, whether it performs format-only or live lookups, or exclusions (e.g., 'use for EORI only'). The context of siblings implies usage, but the description leaves the decision entirely to inference.

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