list_vat_category_codes

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

With no annotations, the description carries the behavioral disclosure burden. It clearly identifies this as a read-only listing operation over a specific code list, which is sufficient given there are no parameters and an output schema exists. It does not discuss ordering or additional return details, but those are not essential for correct invocation.

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 with no filler. Every word contributes meaning: the action, the exact code-system identifier, and the source list.

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 enumeration tool with an output schema, this description is complete. It names the exact code list (UNCL5305) and its source (CEF EN 16931), leaving no ambiguity about what the agent is requesting.

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 properties, so there are no parameters to document. The description correctly adds no parameter-level detail, matching the baseline for a no-parameter tool.

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 ('List'), a precise resource (UNCL5305 VAT category codes), and a named source list (CEF EN 16931). This clearly distinguishes it from the sibling check_vat_category_code, which validates individual codes rather than enumerating them.

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 enumeration use case but provides no explicit when-to-use guidance or alternatives. The existence of check_vat_category_code suggests a related verification tool, but the description never tells the agent when to prefer this list tool over that check tool.

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