invoices_create

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

No annotations are provided, so the description carries the disclosure burden. It states the invoice starts in 'draft' status and can be edited until issued, which is good behavioral context. However, it doesn't disclose the idempotencyKey behavior, collect (immediate payment) side-effects, or what the response/return value contains. The description also doesn't mention VAT calculation behavior, penalty handling, or UBL extensions even though these significantly affect behavior.

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 three sentences, tightly packed with the most essential information: required line items, client identification requirement, and draft-to-issue workflow. It's front-loaded with the primary action. It could mention additional critical requirements but doesn't waste words on trivial content. Slightly more substance than the minimum needed, but still concise.

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 complex 50-parameter tool with two required params and rich nested UBL extension structures, the description covers the essential creation semantics (draft status, editability, requirement constraints, issue follow-up). The schema handles parameter detail comprehensively. The main gap is no mention of return value/created invoice response, no idempotency guidance, and no note about validation behavior. Since output schema is absent, some return-value context would help, but overall it's reasonably complete given the schema richness.

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 all 50 parameters have descriptions within the schema itself. The schema is extremely detailed with descriptions for each parameter including examples, enums, and nested structures. The tool description itself adds only the clientId vs receiverName/receiverCif constraint, which is also largely covered in the schema. Baseline of 3 is appropriate since the schema does the heavy lifting.

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?

The description clearly states the verb (create), resource (draft invoice), and key preconditions (requires line item and clientId or receiverName/receiverCif). It also distinguishes from the sibling tool invoices_issue by clarifying this creates a draft, while issue finalizes. This differentiates it from proforma_invoices_create and delivery_notes_create among siblings.

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 explicitly states required preconditions (at least one line item, either clientId or receiverName/receiverCif) and points to invoices_issue as the follow-up step for finalization and XML/PDF generation. It also clarifies the draft status behavior, giving clear when-to-use guidance versus the issue tool. However, it doesn't contrast with proforma_invoices_create, which could be a near-alternative.

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