VMware-Monitor

list_virtual_machines

Read-onlyIdempotent

List VMware virtual machines with filtering by name or folder, sorting, and field selection. Use it to find a VM by name, then get_vm_info for detail or investigate_vm to drill in.

Instructions

[READ] List virtual machines, with filtering, sorting, and field selection.

Returns the family list envelope {items, returned, limit, total, truncated, hint}; total is the real post-filter count, so read truncated before summarising. Over 50 VMs with no limit/fields, only the first five fields below come back (mode says which). vms is a deprecated pre-1.8.0 alias of items, removed in 2.0 — read items.

Use this to resolve an exact VM name, then get_vm_info for detail or investigate_vm to drill into one; for a fleet-wide view start at get_cluster_health_summary instead.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`limit`	No	Max VMs (None = all).
`fields`	No	Any of name, power_state, cpu, memory_mb, folder_path, guest_os, ip_address, host, uuid, tools_status (None = auto).
`target`	No	vCenter/ESXi target from config (default if omitted).
`sort_by`	No	name \| cpu \| memory_mb \| power_state \| folder_path.	name
`name_filter`	No	Case-insensitive substring of the VM name. Use this to find one VM by name on a large estate — it is what the "VM not found" errors elsewhere tell you to come here for.
`power_state`	No	poweredOn \| poweredOff \| suspended.
`folder_filter`	No	Case-insensitive folder_path substring; nested folders match.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.11.3Sep 12, 2026

addedInput schema / properties / name_filter

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "Case-insensitive substring of the VM name. Use this to find one VM by name on a large estate — it is what the \"VM not found\" errors elsewhere tell you to come here for.",
+  "title": "Name Filter"
+}

Changed7 schema fields changedv1.9.2Aug 31, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / fields / description

Added value: +"Any of name, power_state, cpu, memory_mb, folder_path, guest_os, ip_address, host, uuid, tools_status (None = auto)."

addedInput schema / properties / folder_filter / description

Added value: +"Case-insensitive folder_path substring; nested folders match."

addedInput schema / properties / limit / description
```
Added value: +"Max VMs (None = all)."
```
addedInput schema / properties / power_state / description
```
Added value: +"poweredOn | poweredOff | suspended."
```

addedInput schema / properties / sort_by / description

Added value: +"name | cpu | memory_mb | power_state | folder_path."

addedInput schema / properties / target / description

Added value: +"vCenter/ESXi target from config (default if omitted)."

Changed1 schema field changedv1.5.22May 9, 2026

addedInput schema / properties / folder_filter

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Folder Filter"
+}

Changed5 schema fields changedv1.5.18May 4, 2026

addedInput schema / properties / fields

Added value: +{
+  "anyOf": [
+    {
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Fields"
+}

addedInput schema / properties / limit

Added value: +{
+  "anyOf": [
+    {
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Limit"
+}

addedInput schema / properties / power_state

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Power State"
+}

addedInput schema / properties / sort_by

Added value: +{
+  "default": "name",
+  "title": "Sort By",
+  "type": "string"
+}

changedOutput schema / (root)

Previous value: -{
-  "properties": {
-    "result": {
-      "items": {
-        "additionalProperties": true,
-        "type": "object"
-      },
-      "title": "Result",
-      "type": "array"
-    }
-  },
-  "required": [
-    "result"
-  ],
-  "title": "list_virtual_machinesOutput",
-  "type": "object"
-}New value: +null

First observedv0.1.2Mar 8, 2026

TDQS

A4.8/5.0

Behavior5/5

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

With annotations already declaring readOnly/idempotent/non-destructive, the description goes well beyond: it discloses the truncated result envelope, that `total` is post-filter, that >50 VMs with no limit/fields returns only the first five fields (mode says which), and that `vms` is a deprecated pre-1.8.0 alias removed in 2.0. These are real behavioral constraints an agent would otherwise miss.

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?

Front-loaded with purpose and routing, and every sentence carries behavioral weight. The envelope-key enumeration is slightly dense and could be trimmed, but it substitutes for a missing output schema, so it earns its place.

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?

This is a 7-param, no-output-schema listing tool, so the description must carry the return-shape burden — and it does, naming the envelope keys, the truncated flag, the mode field, and the deprecated alias. Nothing an agent needs to call and interpret it correctly is missing.

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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning: it explains the limit/fields interaction that triggers truncation and singles out name_filter as the tool's intended mechanism for locating a VM by name. That is value beyond the per-parameter schema text.

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?

Opens with a specific verb+resource and scope ("List virtual machines, with filtering, sorting, and field selection") and immediately distinguishes itself from siblings by naming get_vm_info, investigate_vm, and get_cluster_health_summary as the routes for other needs. An agent can tell exactly what this tool is for without opening the schema.

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

Usage Guidelines5/5

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

States a concrete use case ("resolve an exact VM name") and explicit routing: get_vm_info for detail, investigate_vm to drill in, get_cluster_health_summary for a fleet-wide view. Alternatives are named with the conditions that select them, leaving nothing to inference.

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

list_virtual_machines

Instructions

Input Schema

Schema Changelog

TDQS

Other Tools