# list_instance_group_managers

Lists Compute Engine managed instance groups (MIGs). Details for each MIG include name, ID, instance template, base instance name, target size, target stopped size, target suspended size, status and creation timestamp. Requires project and zone as input.

Agent View of the PolicyLayer registry record for `list_instance_group_managers`. HTML page: https://policylayer.com/tools/com-googleapis-compute-mcp/list-instance-group-managers

## Facts

- Tool: `list_instance_group_managers`
- 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: 4 (2 required)
- Recommended policy verdict: Allowed

## Parameters

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

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_instance_group_managers",
    "arguments": {
      "zone": "<zone>",
      "project": "<project>"
    }
  }
}
```

## Why list_instance_group_managers is rated Low

This tool retrieves and queries infrastructure metadata without creating, modifying, deleting, or executing any operations. It is a purely informational API call that reads existing resource state. The blast radius of misuse is minimal—an agent could only gather information about existing MIGs, not alter or delete them.

From the tool's own definition: "Tool description states it 'Lists Compute Engine managed instance groups' and returns details like name, ID, instance template, base instance name, target size, status and creation timestamp."

## Use case

AI agents call list_instance_group_managers 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_instance_group_managers": {}
  }
}
```

## 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_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_managed_instances` — Read — https://policylayer.com/tools/com-googleapis-compute-mcp/list-managed-instances.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