Get Natura Codes

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

With no annotations, the description carries the full burden, and it delivers: 'Always succeeds' plus an explicit return contract {'codes': [...], 'total': int}. The note about parent codes N2/N3/N6 being removed from the FatturaPA XSD in 2021 is a non-obvious, valuable behavioral/domain detail that prevents agents from using obsolete codes.

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 information-dense without bloat: purpose, trigger condition, common-code examples, an important caveat, and return format are each covered in a compact, well-structured block. No sentence is redundant or filler.

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 lookup with an output schema, the description is complete: it gives the trigger context, expected output shape, success guarantee, and the legal/version constraints around valid codes. An agent has everything needed to decide to call it and interpret the result 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?

The tool has zero parameters, so the schema coverage is trivially 100% and the baseline is 4. There are no parameter-level semantics to add, and the description appropriately focuses on when the tool should be invoked instead.

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 ('Return') and resource ('complete list of valid Natura exemption codes with legal references'), immediately telling the agent what the tool does. The trigger condition ('when add_linea_dettaglio() requires a Natura code') further pins down its purpose and distinguishes it from sibling code-list tools by subject matter.

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?

'Call this when add_linea_dettaglio() requires a Natura code (i.e. aliquota_iva is 0.0)' is an explicit, actionable condition for when to use the tool. However, it does not name when-not cases or alternative lookup tools, so it stops short of the full when/when-not/alternatives guidance required for a 5.

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