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

With no annotations, the description carries the full burden and does well: it discloses that the emitted document is fiscally valid and can only be undone via formal annulment — a critical irreversibility warning. It omits other operational traits such as SIAT credential/auth requirements or failure modes (e.g., rejected NIT or offline state), which keeps it from a 5.

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 sentences, front-loaded with what the tool does and immediately followed by the mandatory confirmation gate and the return payload. No sentence is redundant.

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?

Return values are enumerated (CUF, invoice number, amount in words, PDF links), which is necessary since there is no output schema, and the confirmation workflow is spelled out. But for a 6-parameter tool with nested objects and only 33% schema coverage, the description leaves too much of the invocation surface undocumented.

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 description coverage is only 33% across 6 parameters including a nested items array and cliente object, so the description needs to compensate but does not. It only loosely gestures at 'cliente, ítems, precios y total' for the confirmation summary and says nothing about actividad_economica codes, sucursal/punto_venta defaults, or metodo_pago effects.

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 and resource: it issues a fiscal Compra y Venta invoice against Bolivia's SIAT. The scope qualifier ('Sector 1') and the mention of the emitted fiscal document clearly separate it from the query-oriented siblings such as consultar_factura and listar_facturas.

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 an explicit precondition for calling: show the user the full summary and wait for confirmation. However, it never names an alternative for read-only or draft scenarios, nor states when this tool should not be used, so the routing guidance is contextual rather than exhaustive.

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