Mark Invoice Paid

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

The description adds value beyond annotations by noting the default payment date behavior. Annotations already indicate idempotency and non-destructive nature, so the description's additional context is helpful but not extensive.

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 concise and front-loaded with the core action. The bilingual text adds length but is acceptable. Every sentence provides value, making it efficient.

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?

Given the simple tool and available output schema, the description covers the essential functionality. It might lack details about prerequisites or error states, but it is sufficiently complete for a straightforward operation.

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 coverage is 100%. The description adds meaning by explaining the default behavior for paidDate and confirming the id parameter's purpose. This enhances understanding beyond the schema alone.

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 action ('Mark an invoice as paid') and the specific resource ('invoice'). It distinguishes from sibling tools like create_invoice, delete_invoice, or send_invoice by focusing on the specific status change.

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 provides clear context: when to use the tool (to mark an invoice as paid) and optional parameters. However, it does not explicitly mention when not to use it or suggest alternatives like apply_deposit, which could be a related action.

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