Horizon MCP Server

machine_action

Destructive

Perform bulk actions on Horizon VDI machines, including shutdown, restart, reset, rebuild, recover, maintenance mode changes, and archive.

Instructions

Perform a bulk action on one or more machines.

Actions:

shutdown: gracefully power off (use force=true to override active sessions)
restart: reboot the machine (use force=true to override active sessions)
reset: hard reset (power cycle) — may cause data loss
rebuild: re-provision the machine from the pool's image
recover: recover a machine stuck in an error state
enter_maintenance: put machine into maintenance mode (prevents new sessions)
exit_maintenance: take machine out of maintenance mode
archive: initiate machine archival

CAUTION: rebuild and reset are destructive and will discard unsaved user data. Always confirm with the user before calling these actions.

Input Schema

TableJSON Schema

Name	Required	Description
`force`	No	Force the operation even if sessions are active. Only applies to shutdown and restart — raises an error for other actions.
`action`	Yes	Action to perform on the machines
`confirm`	No	Only used when the server runs with HORIZON_CONFIRMATION=flag (clients without elicitation). Otherwise the user is asked to confirm directly in the client.
`machine_ids`	Yes	List of machine IDs to act on

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.2.0Sep 30, 2026

addedInput schema / properties / confirm

Added value: +{
+  "default": false,
+  "description": "Only used when the server runs with HORIZON_CONFIRMATION=flag (clients without elicitation). Otherwise the user is asked to confirm directly in the client.",
+  "type": "boolean"
+}

First observedv0.1.0Sep 10, 2026

TDQS

A4.5/5.0

Behavior5/5

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

Annotations give only a blanket destructiveHint=true; the description goes further by naming which specific actions are destructive (reset, rebuild), warning that unsaved user data is discarded, noting reset is a hard power cycle, that maintenance mode prevents new sessions, and that force only applies to shutdown/restart. This is materially more useful than the annotation alone.

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?

Front-loaded one-line purpose followed by a compact per-action bullet list and a caution block; every sentence carries information and a reader can scan to the relevant action immediately.

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

Completeness5/5

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

Given an output schema exists, the description need not cover return values, and it supplies everything else an agent needs: the full action vocabulary, which actions are destructive, force applicability, and confirmation behavior. No material gap remains for correct invocation.

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 description coverage is 100% and each parameter is already documented in the schema, including force's restriction to shutdown/restart. The prose repeats that force overrides active sessions but adds no syntax, format, or edge-case detail beyond the structured fields, so baseline 3 applies.

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?

States a specific verb (bulk action) and resource (machines) and enumerates the exact action set. It is clearly distinguishable from sibling action tools like desktop_pool_action and rdsh_farm_action by scoping to machines.

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?

Each action carries inline guidance (force semantics, when to use recover, that maintenance blocks new sessions) and there is an explicit caution plus a directive to confirm destructive actions with the user. What is missing is routing guidance against alternatives such as desktop_pool_action or when to use single-machine tools instead.

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

Deploy Server