mcp-server-smallinvoice

send_invoice_by_post

Send an invoice by post with configurable color, duplex/simplex printing, and priority/economy speed.

Instructions

Sends specified invoice by post (SENDS BY POST — irreversible)

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "invoice_id": "<invoice_id>",
      "palette": "<palette>",
      "print": "<print>",
      "speed": "<speed>"
    },
    "name": "send_invoice_by_post"
  }
}

Input Schema

Name	Required	Description
`invoice_id`	Yes	invoice ID
`palette`	Yes	palette; possible values: C - colour, BW - black&white
`print`	Yes	printing type; possible values: D - duplex (two-sided), S - simplex (one-sided)
`speed`	Yes	sending speed; possible values: P - priority, E - economy

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0May 29, 2026

TDQS

A3.6/5.0

Behavior3/5

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

Annotations indicate it's not read-only and not destructive, but the description adds the key behavioral trait of irreversibility. However, it does not detail other effects (e.g., status changes, costs) or confirm that the action is irreversible for the sent item itself.

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?

The description is a single, efficient sentence that conveys core purpose and a key caveat (irreversibility). It is not verbose, though it could potentially include more context without losing conciseness.

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 tool with 4 required parameters and no output schema, the description covers basic purpose and irreversibility but lacks details on process effects (e.g., invoice status changes) or prerequisites. It is adequate but not fully complete.

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 coverage is 100% with descriptions for all parameters (invoice_id, palette, print, speed). The description adds no extra meaning beyond the schema, so baseline score of 3 is appropriate.

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

Purpose5/5

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

The description states a specific verb ('sends') and resource ('invoice by post'), clearly distinguishing it from siblings like send_invoice_by_email or send_offer_by_post. The emphasis on 'irreversible' adds further clarity.

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

Usage Guidelines3/5

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

The description implies usage (sending invoices by post) but provides no explicit guidance on when to choose this over alternatives (e.g., email) or any prerequisites (e.g., invoice status). The irreversibility hint is useful but not a full guideline.

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

Deploy Server