Email an invoice to its customer, automatically retrieving sender and customer email addresses.
Email an invoice to its customer. Looks up the sender address and the customer's email automatically.
| Name | Required | Description | Default |
|---|---|---|---|
| body | No | ||
| subject | No | ||
| invoiceId | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It usefully discloses that the sender address and customer email are looked up automatically (no need to supply them), but omits the permission requirements, the irreversible side effect of actually sending email, and any rate limits or state preconditions.
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?
Two short sentences with zero waste; the core action is front-loaded and the helpful auto-lookup detail follows immediately.
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?
For a side-effecting action tool with no annotations, no output schema, and 0% parameter coverage, the description is minimal but covers the core purpose. It leaves preconditions, side-effect behavior, and the subject/body parameters unexplained.
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 description coverage is 0%, so the description must compensate, yet it only implicitly identifies invoiceId and says nothing about the optional subject and body overrides. The automatic-lookup note implies sender/customer params are unnecessary but the two remaining parameters are entirely undocumented.
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?
States a specific verb and resource ('Email an invoice') and clearly distinguishes itself from siblings like create_invoice, update_invoice, and delete_invoice. An agent can tell this is the send/dispatch action without opening the schema.
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?
Usage is implied by the verb 'Email' but there is no explicit when-to-use guidance, no mention of prerequisites (e.g. whether the invoice must be in a finalized state), and no routing versus alternatives such as send_estimate or create_invoice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.