Proxmox MCP Server

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

No annotations provided, so description carries full burden. It successfully discloses the external dependency (QEMU guest agent), installation requirements, and enumerates return fields (mount points, total size, used/free space, filesystem type). Could be improved by describing error behavior when the agent is unavailable.

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

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

Well-structured with clear sections (purpose, prerequisites, args, returns). Front-loaded with the core action. Installation commands are slightly verbose but provide necessary troubleshooting context. The 'Args:' and 'Returns:' sections effectively compensate for the undescribed schema without excessive wordiness.

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

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

Given zero annotations and zero schema description coverage, the description successfully covers the critical prerequisite (guest agent), parameter meanings, and output structure. The context signals indicate an output schema exists, so the description appropriately summarizes rather than exhaustively documents return values.

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

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

Schema has 0% description coverage, requiring full compensation by the description. The text adequately documents both parameters: 'vmid: The VM ID' and 'node: The Proxmox node name (optional, will auto-detect)'. This provides sufficient semantic meaning for the agent to understand parameter purposes, though it lacks format constraints or examples.

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

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

Excellent specificity with verb 'Get' + resource 'filesystem/disk space information from inside a VM' + mechanism 'using the QEMU guest agent'. The mention of the guest agent clearly distinguishes this from sibling tools like get_vm_info or get_vm_metrics which likely operate at the hypervisor level.

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

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

Strong prerequisite disclosure: explicitly states 'requires the qemu-guest-agent to be installed and running' and provides installation commands for Debian/Ubuntu and RHEL/CentOS. This effectively signals when the tool will/won't work. Lacks explicit mention of alternatives if the agent is unavailable.

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