create_invoice

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

With no annotations, the description carries full burden for behavioral disclosure. It only mentions 'draft invoice' but omits important traits such as whether the invoice is editable after creation, any workflow triggers, or required permissions.

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 contains an Args block that adds structure but is somewhat verbose. Each sentence is informative, but front-loading could be improved. A more concise version might say 'Creates a draft invoice with required debtor_code and invoice_lines, plus optional extra_fields.'

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?

While an output schema exists, the description does not mention return values or side effects. Given the complexity (3 parameters, one nested array, one catch-all object), the description is adequate but could be improved by noting that the tool returns something (e.g., invoice ID).

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 0%, so the description compensates well. It explains debtor_code with an example, describes invoice_lines composition (ProductCode or free-form fields), and clarifies extra_fields as catch-all for invoice-level fields.

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 'Create a draft invoice,' which is a specific verb+resource combination. It distinguishes this tool from siblings like credit_invoice and send_invoice.

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?

No explicit guidance on when to use this tool versus alternatives. The description merely states what it does, without indicating when it is appropriate or when other tools should be preferred.

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