Unofficial-Proxmox-MCP

pve_resize_disk

Expand a Proxmox VE virtual disk or container root filesystem by a specified number of gigabytes, increasing storage capacity without recreating the disk. Specify VM/CT ID, disk device, and size to add.

Instructions

Incrementally expand the storage capacity of a virtual disk.

Args: vmid: Target VM or Container ID. disk: Disk device identifier (e.g. 'scsi0', 'virtio0', or 'rootfs'). add_gb: Size in gigabytes to expand by (e.g. 10 adds 10GB). node: Optional node name.

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": {
      "vmid": "<vmid>",
      "disk": "<disk>",
      "add_gb": "<add_gb>"
    },
    "name": "pve_resize_disk"
  }
}

Input Schema

Name	Required	Description	Default
`disk`	Yes
`node`	No
`vmid`	Yes
`add_gb`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Nov 9, 2026

TDQS

B3.1/5.0

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 behavioral burden, and it leaves the most important traits unstated: that this is a destructive/irreversible mutation of VM configuration, that it only grows (the word 'incrementally' hints at grow-only but never says shrinking is rejected), and that the guest filesystem usually must be expanded separately afterwards. Only the growth direction is faintly implied.

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?

One summary sentence followed by a structured Args list — front-loaded and free of padding. The parameter list earns its space because the schema has no descriptions, and the only minor inefficiency is the parenthetical example duplicating the sentence's meaning.

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?

An output schema exists, so return values need not be explained, and the four parameters are covered. For a no-annotation mutation tool on VM storage, however, the definition is thin on the operational facts an agent needs: required guest power state, irreversibility, and follow-up filesystem growth.

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

Parameters4/5

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

Schema description coverage is 0%, so the Args block is doing real work: it explains vmid as the target VM/Container ID, gives concrete disk identifier examples ('scsi0', 'virtio0', 'rootfs'), clarifies that add_gb is a delta rather than a target size ('10 adds 10GB'), and marks node as optional. This meaningfully exceeds the bare typed properties, though units/constraints on add_gb are still unstated.

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 states a specific verb and resource: 'Incrementally expand the storage capacity of a virtual disk.' That is unambiguous and no sibling tool in the list performs disk resizing, so the purpose stands apart. It stops short of a 5 only because it never explicitly frames itself against the other mutation tools (edit_system, clone_system).

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 prerequisites, and no conditions under which this tool should be avoided. Nothing says whether the guest must be stopped, whether the disk must already exist and be attached, or what to do instead if the goal is to shrink or move a disk.

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