create_invoice

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

The annotations only indicate readOnlyHint=false and destructiveHint=false; the description adds valuable behavioral context by warning that the contact must already have a tax_id or Quipu will reject the invoice, and that the invoice is 'issued' rather than draft. This goes meaningfully beyond the annotations.

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?

Two sentences with no filler: the first states the action, the second provides the required inputs and the critical rejection condition. Every sentence contributes distinct, necessary information.

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?

The description covers the action, minimum inputs, and a domain-specific failure condition, which is sufficient for a guided call. The only gap is no mention of the return value or side effects such as immutability, but there is no output schema and the core invocation requirements are fully present.

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 100%, so the baseline is 3. The description adds value by highlighting the two required parameters and, more importantly, introducing the tax_id precondition on the contact, which is not present anywhere in the schema. It doesn't describe other parameter formats, but the schema already covers them.

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 action ('Create an issued invoice'), a platform ('Quipu'), and the core requirements. The word 'issued' meaningfully distinguishes this from draft creation and from sibling tools like update_invoice, delete_invoice, and list_invoices.

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 clearly conveys when to use the tool: to create an issued invoice, and it gives concrete prerequisites (contact_id, at least one line item, existing tax_id). It doesn't explicitly mention alternatives, but there is no competing create tool among the siblings, so the context is sufficient.

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