send_invoice_email

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

No annotations are provided, so the description carries full burden. It only states that an email is sent with optional overrides. It does not disclose behavioral aspects like whether the invoice status changes, if the action is reversible, delivery confirmation, rate limits, or authorization requirements. This is insufficient for a mutating action.

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 a single, clear sentence that states the core action and key behavior (template override). Every word earns its place, with no redundancy or unnecessary details.

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 tool has 5 parameters and no output schema, the description adequately explains the main function and template override. However, it lacks context on constraints (e.g., invoice must be finalized, email configuration required) and does not describe what happens after sending. It is adequate but could be more thorough.

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%, with parameter descriptions in the schema. The description adds value by explaining that 'message' and 'subject' override the default template, which is not in the schema. This gives semantic context beyond the basic field descriptions.

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 ('Email an invoice') and the resource ('to the client'), distinguishing it from sibling tools that deal with creating, listing, or exporting invoices. No sibling tool has 'email' in its name, so purpose is 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?

The description mentions using the default template unless overridden, giving some usage context. However, it does not specify when to use this tool versus alternatives like export_invoice_pdf, nor does it mention prerequisites such as invoice status or required permissions. Guidance is minimal.

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