mcp-snap7

by daedalus

Overview Schema Source Related Servers Discussions Admin

Python

Local

connect_plc

Connect to a Siemens PLC via IP address, rack, slot, and TCP port to enable data exchange and PLC interaction.

Instructions

Connect to a Siemens PLC.

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": {
      "address": "<address>"
    },
    "name": "connect_plc"
  }
}

Input Schema

Name	Required	Description
`address`	Yes	PLC IP address (e.g., "192.168.1.1")
`rack`	No	Rack number (default 0)
`slot`	No	Slot number (default 1)
`tcp_port`	No	TCP port (default 102)

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 8, 2026

TDQS

C2.9/5.0

Behavior2/5

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

The description is minimal and does not disclose important behavioral traits such as connection persistence, timeout behavior, or error handling. Since no annotations are provided, the description carries the full burden of transparency, which it fails to meet.

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 sentence with no wasted words. However, it could be slightly expanded with key context without becoming verbose.

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

Completeness2/5

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

Given that this is a connection tool with an output schema, the description lacks completeness on behavior (e.g., connection state, return values, timeout). It does not explain what happens on success or failure beyond just 'connect'.

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?

All four parameters are well-described in the input schema (100% coverage), so the description adds no additional meaning beyond 'Connect to a Siemens PLC'. Baseline 3 is appropriate as the schema already documents parameter semantics.

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

Purpose4/5

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

The description 'Connect to a Siemens PLC' is clear about the verb and resource. It distinguishes from siblings like 'disconnect_plc' and 'get_connected', but does not elaborate on what the connection entails or how it differs from other connection tools.

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?

No guidance on when to use this tool versus alternatives. For example, it doesn't mention prerequisites (e.g., network access), when not to use (e.g., if already connected), or relation to other tools like 'disconnect_plc'.

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