# list_managed_instances

Lists managed instances for a given managed instance group (MIG). For each instance, details include id, instance URL, instance status, and current action. Requires project, zone, and MIG name as input.

Agent View of the PolicyLayer registry record for `list_managed_instances`. HTML page: https://policylayer.com/tools/com-googleapis-compute-mcp/list-managed-instances

## Facts

- Tool: `list_managed_instances`
- Server: Mcp (`https://compute.googleapis.com/mcp`) — https://policylayer.com/tools/com-googleapis-compute-mcp.md
- Homepage: https://github.com/https://compute.googleapis.com/mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 5 (3 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `name` | string | yes | Required. Identifier. The instance group manager name. |
| `zone` | string | yes | Required. The zone of the instance group manager. |
| `project` | string | yes | Required. Project ID for this request. |
| `pageSize` | integer | no | Optional. The maximum number of managed instances to return. |
| `pageToken` | string | no | Optional. A page token received from a previous call to list managed instances. |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "list_managed_instances",
    "arguments": {
      "name": "<name>",
      "zone": "<zone>",
      "project": "<project>"
    }
  }
}
```

## Why list_managed_instances is rated Low

This tool retrieves and queries infrastructure metadata about managed instances within a specified managed instance group. It has no side effects, does not modify or delete any resources, and does not execute arbitrary code or commands. It is a pure data retrieval operation that returns existing instance information.

From the tool's own definition: "Tool name is 'list_managed_instances' and description states it 'Lists managed instances' with details returned including id, instance URL, status, and action."

## Use case

AI agents call list_managed_instances to retrieve information from Mcp without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mcp:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_managed_instances": {}
  }
}
```

## Other tools on Mcp (28)

- `delete_instance` — Destructive — https://policylayer.com/tools/com-googleapis-compute-mcp/delete-instance.md
- `reset_instance` — Execute — https://policylayer.com/tools/com-googleapis-compute-mcp/reset-instance.md
- `start_instance` — Execute — https://policylayer.com/tools/com-googleapis-compute-mcp/start-instance.md
- `stop_instance` — Execute — https://policylayer.com/tools/com-googleapis-compute-mcp/stop-instance.md
- `get_commitment_basic_info` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-commitment-basic-info.md
- `get_disk_basic_info` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-disk-basic-info.md
- `get_disk_performance_config` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-disk-performance-config.md
- `get_instance_basic_info` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-instance-basic-info.md
- `get_instance_group_manager_basic_info` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-instance-group-manager-basic-info.md
- `get_instance_template_basic_info` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-instance-template-basic-info.md
- `get_instance_template_properties` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-instance-template-properties.md
- `get_reservation_basic_info` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-reservation-basic-info.md
- `get_reservation_details` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-reservation-details.md
- `get_zone_operation` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/get-zone-operation.md
- `list_accelerator_types` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-accelerator-types.md
- `list_commitment_reservations` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-commitment-reservations.md
- `list_commitments` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-commitments.md
- `list_disks` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-disks.md
- `list_images` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-images.md
- `list_instance_attached_disks` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-instance-attached-disks.md
- `list_instance_group_managers` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-instance-group-managers.md
- `list_instance_templates` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-instance-templates.md
- `list_instances` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-instances.md
- `list_machine_types` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-machine-types.md
- `list_reservations` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-reservations.md
- `list_snapshots` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-snapshots.md
- `create_instance` — Write — https://policylayer.com/tools/com-googleapis-compute-mcp/create-instance.md
- `set_instance_machine_type` — Write — https://policylayer.com/tools/com-googleapis-compute-mcp/set-instance-machine-type.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-googleapis-compute-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-googleapis-compute-mcp