send_invoice

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

The description adds no behavioral context beyond annotations. It does not disclose what happens to invoice status, whether an email is actually sent, or potential side effects. However, it does not contradict annotations.

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 three-word fragment is under-specified, not concise. It lacks sufficient content to inform the agent, making it closer to a placeholder than a useful description.

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?

With 6 params and no output schema, a one-line description is inadequate. It does not cover return values, possible errors, or side effects, despite the tool's modesty.

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 already covers 4/6 params with descriptions, but 2 params (subject, mark_as_open) are undocumented. The description adds no parameter information, leaving the agent to infer the meaning of 'subject' and the boolean flag.

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 verb 'send' and resource 'invoice', but it is generic and does not specify the actual behavior (e.g., email dispatch vs. status update). It does not differentiate from siblings like send_invoice_reminder or mark_as_sent_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 guidance is provided on when to use this tool over alternatives. There is no mention of prerequisites, context, or exclusions.

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