Create reverse (storno) invoice

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

Annotations set readOnlyHint=false and destructiveHint=false. The description adds that this creates a new fiscal document and that both documents remain and cancel out, which is useful context. It does not contradict annotations, and the confirmation warning adds transparency. However, it could mention side effects like potentially affecting accounting periods.

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 four sentences long, front-loaded with purpose and usage guidance. Every sentence adds value, and there is no unnecessary repetition or fluff.

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 when to use, alternatives, and a confirmation warning. Given the lack of output schema, it could be more complete by briefly stating what the response contains or if any side effects occur (e.g., immediate posting to accounting). However, it is fairly complete for the tool's complexity.

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 schema already documents each parameter. The description adds minor context (e.g., 'into the same series', fallback defaults) but does not significantly enhance understanding of parameter usage beyond the schema.

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 tool issues a storno invoice that reverses an existing invoice in full into the same series. It uses a specific verb ('Issue') and resource ('storno invoice'), and distinguishes it from siblings like cancel_invoice and delete_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?

The description explicitly states when to use (invoice too old to delete, needs to appear in books) and when not to (use cancel_invoice for voiding, or issue a new invoice with negative quantities for partial corrections). It also advises confirming with the user before calling.

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