Proxmox MCP Server

create_firewall_rule

Create firewall rules for Proxmox cluster or nodes, specifying action, protocol, and addresses to control network traffic.

Instructions

Create a firewall rule

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": {
      "action": "<action>",
      "type": "<type>"
    },
    "name": "create_firewall_rule"
  }
}

Input Schema

Name	Required	Description
`dest`	No	Destination address or network (CIDR)
`type`	Yes	Rule type: "in", "out", or "group"
`dport`	No	Destination port or port range
`proto`	No	Protocol (e.g. "tcp", "udp", "icmp")
`scope`	No	Scope: "cluster" for cluster-level rules, or a node name for node-level rules. Defaults to cluster.
`sport`	No	Source port or port range
`action`	Yes	Rule action: "ACCEPT", "DROP", or "REJECT"
`enable`	No	Whether the rule is enabled (1/true or 0/false)
`source`	No	Source address or network (CIDR)
`comment`	No	Rule comment

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jul 12, 2026

TDQS

B3.1/5.0

Behavior2/5

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

The description discloses no behavioral traits beyond what annotations provide (destructiveHint=false). It does not mention that creating a rule is a write operation, potential network impact, permission requirements, or any side effects.

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 clear sentence with no wasted words. However, for a tool with 10 parameters, it could benefit from brief structure, but it is not overly 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 10 parameters and no output schema, the description is insufficient. It does not explain what happens after creation (e.g., return value, rule ID), nor does it provide context on how the rule is applied or any default behavior (e.g., scope defaults to cluster).

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%, so the baseline is 3. The description adds no extra meaning about parameters beyond what the schema already describes, such as the scope or action values.

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 'Create a firewall rule' clearly states the action (create) and resource (firewall rule), distinguishing it from sibling tools like delete_firewall_rule and list_firewall_rules, as well as other create_* tools for different resources.

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?

The description provides no guidance on when to use this tool versus alternatives, nor does it mention prerequisites like specifying cluster vs node scope. The intended usage is only implied by the tool name.

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

Deploy Server