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Glama

qemu_snapshot_create

Destructive

Create a named disk snapshot for a stopped VM to preserve state and enable rollback to a known-good configuration.

Instructions

Create a named qcow2 internal disk snapshot while the VM is stopped.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
nameYes
vm_idYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. Addedv1.6.0

TDQS

A3.8/5.0
Behavior3/5

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

Annotations already mark this as destructive and non-read-only. The description adds useful context: it is an internal qcow2 snapshot and requires a stopped VM. However, it does not disclose failure behavior, side effects on the disk, or what happens if the VM is running.

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

Conciseness5/5

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

The description is one tight sentence with no filler. The action ('Create'), object ('named qcow2 internal disk snapshot'), and precondition ('while the VM is stopped') are all front-loaded and directly useful.

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 two-parameter tool, the description captures the essential precondition and resource type. However, with no output schema and minimal parameter explanation, it leaves gaps around return behavior, failure modes, and the relationship between this snapshot and the restore/delete/list siblings.

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

Parameters2/5

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

Schema description coverage is 0%, so the description must compensate. It references 'a named ... snapshot' and 'the VM', which weakly maps to the name and vm_id parameters, but it does not explain that vm_id identifies the target stopped VM or that name must be a unique snapshot label. This is insufficient for full parameter understanding.

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 uses a specific verb ('Create') and resource ('named qcow2 internal disk snapshot'), plus a key condition ('while the VM is stopped'). This clearly distinguishes it from siblings such as qemu_snapshot_restore, qemu_snapshot_delete, and qemu_snapshot_list.

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

Usage Guidelines4/5

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

The description explicitly states the required precondition: the VM must be stopped. It does not name alternatives or state when not to use this tool, so it stops short of full guidance, but the main usage context is clear.

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