send_draft_order_invoice

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

No annotations are provided, so the description carries full responsibility. It explicitly discloses that an email is sent to the customer and that the draft status changes to 'invoice_sent', which are critical behavioral traits. This is strong transparency, though it doesn't cover failure scenarios.

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 two sentences long, front-loads the primary action, and includes only essential information about side effects and requirements. No unnecessary words.

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 purpose, side effects, and a prerequisite. Given the tool's moderate complexity (5 parameters, no output schema), this is sufficient for an agent to select and invoke it correctly. It doesn't describe return values, but those are not needed for understanding the tool's function.

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%, and the description adds meaning by noting that the 'to' parameter can substitute for a missing customer email. This connects the parameter to the prerequisite. Other parameters remain self-explanatory via 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 states the specific action ('Send an invoice email') and resource ('draft order'), and the side effect of status change differentiates it from related tools like complete_draft_order. It is clear and unambiguous.

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?

Provides a clear precondition: requires customer email on the draft or via the 'to' parameter. This indicates when the tool is applicable, but it does not explicitly name alternative tools or state when not to use it, so it falls short of a full 5.

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