list_vat_category_codes

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

With no annotations provided, the description carries the full burden. It discloses the operation (list) and the source code list, but does not mention behaviors such as whether all codes are returned, ordering, or potential size. The output schema likely covers return shape, but behavioral context beyond that is minimal.

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 immediately states the action and scope. There is no filler, repetition, or unnecessary detail.

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 zero-parameter list operation with an output schema available, the description is largely complete: it names the resource and authoritative source. It could be slightly more complete by explicitly noting that this is the enumeration counterpart to check_vat_category_code, but that is a minor 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?

The input schema has zero parameters, so there is nothing for the description to clarify about parameters. The baseline for a zero-parameter tool is 4, and the description correctly communicates that no input is needed.

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 names a specific verb ('List'), a specific resource ('UNCL5305 VAT category codes'), and the source ('CEF EN 16931 code list'). This clearly distinguishes it from the sibling check tool 'check_vat_category_code' and from other code-list listing tools.

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 implies the tool is for enumerating VAT category codes, but it does not explicitly state when to use this list tool versus check_vat_category_code. The intended usage is inferable from the name and sibling set, but no direct guidance or exclusions are provided.

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