iec-mcp

list_invoices

Retrieve a contract's invoices, including amounts, payment status, billing periods, and consumption. Filter by contract, business partner, or show only unpaid bills.

Instructions

A contract's invoices: amounts, paid status, billing periods and consumption.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_invoices"
  }
}

Input Schema

Name	Required	Description
`bpNumber`	No	Business partner number; defaults to the signed-in customer's.
`onlyOpen`	No	Only unpaid invoices.
`contractId`	No	Contract number; defaults to the first contract.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 17, 2026

TDQS

C2.7/5.0

Behavior2/5

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

No annotations are supplied, so the description carries the full disclosure burden, yet it only enumerates returned data fields. It says nothing about whether this is a safe read, authorization requirements, pagination, result limits, or what happens when no contract exists beyond the schema's 'defaults to the first contract' note.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single compact sentence with no filler, front-loaded on the resource. It is efficient, though the terseness shades into under-specification rather than being deliberately economical.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only list tool with no output schema, the description usefully enumerates the returned fields, which partially covers the missing return documentation. It still omits usage context, auth expectations, and result-size behavior, and with no annotations there is nothing else to fill those gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all three parameters (bpNumber, onlyOpen, contractId) are already documented with defaults and meaning. The description adds no parameter-level detail beyond the schema, which is the expected baseline when the schema does the work.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose3/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description names the resource and its payload (a contract's invoices with amounts, paid status, billing periods, consumption), so the agent can guess this is a listing/retrieval tool. However, it is a bare noun phrase with no verb and no explicit scope such as 'lists all invoices for a contract', and it does not distinguish itself from siblings like get_invoice_pdf or get_electric_bill beyond the field list.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no when-to-use guidance, no mention of prerequisites (e.g., needing a signed-in customer or contract), and no routing to alternatives. The sibling get_invoice_pdf and get_electric_bill are never referenced, leaving the agent to infer which tool to pick.

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

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