Create a new recurring invoice

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

Annotations already provide readOnlyHint=false, destructiveHint=false, and idempotentHint=false, covering the write nature and non-idempotency. The description adds a procedural note about checking option combinations but does not disclose the response format, potential side effects, or required permissions. It does not contradict the annotations, so a mid score is appropriate.

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 begins by repeating the title verbatim ('Create a new recurring invoice.') which is redundant. The subsequent information about options and line types is valuable and well-structured, but the duplication and the trailing '[Recurring Invoices] POST /invoices/recurring' line add noise. It is not overly long, but could be tighter.

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 tool has a rich input schema with many parameters and nested objects, but no output schema. The description provides critical guidance on line types and the prerequisite options call, but omits any information about the response or what happens after creation. Given the complexity of the operation and the lack of an output schema, a description that does not explain return values or follow-up actions is not fully complete.

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?

The description adds meaningful context beyond the schema by explaining the difference between regular lines (qty, amount, vat_id, ledger_id) and info lines (info=true and description). It also mentions the dependency between vat_id, ledger_id, and vat_option, which is not immediately obvious from the schema alone. Schema descriptions are already detailed for many fields, but the description helps prioritize prerequisites.

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 new recurring invoice' with a specific verb and resource. It also explains the two line types (regular vs info) and references the options endpoint, which helps distinguish it from sibling tools like create_sales_invoice or create_purchase_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 instructs to use the /invoices/recurring/options endpoint first to validate VAT/ledger combinations, providing a prerequisite step. It explains when to use info lines versus regular lines. However, it does not explicitly mention when not to use this tool or compare with alternatives, leaving some inference to the agent.

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