create_vat_type

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

No annotations are supplied, so the description carries the full burden. It discloses that `data` follows the Fatture in Cloud API v2 schema and adds a real behavioral constraint (ei_type needed for non-VAT natures), but says nothing about required permissions, whether creation is idempotent, what happens on duplicate rates, or what is returned.

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?

Three short sentences, front-loaded with the action and then the payload convention. No filler, though the API-version reference is terse enough that it may leave the reader needing external documentation.

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 mutation tool with a nested free-form object and no annotations or output schema, the definition covers the essential shape but outsources field-level detail to an external API doc the agent may not have. Return values and error behavior are omitted, which is acceptable only because there is no output schema to lean on.

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?

Schema coverage is 50%: company_id is documented in the schema, while `data` is an opaque object with additionalProperties. The description partially compensates by pointing to the API v2 schema and naming the ei_type field, but it does not enumerate the fields `data` accepts, leaving the main parameter underspecified.

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 ("Crea") and resource ("un aliquota IVA o natura di esenzione"), so the agent knows this creates a VAT rate or exemption nature. It does not explicitly contrast itself with update_vat_type, but the create verb makes the distinction from update/list/get siblings clear enough.

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?

Gives one useful conditional: for operations without VAT, supply ei_type (nature, e.g. N2.2) plus a regulatory description/reference. It does not say when to use this versus update_vat_type or duplicate an existing rate, nor mention prerequisites like permissions.

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