restore_backup · Storage MCP: Risk & Policy

WHAT IT DOES

What restore_backup does on Storage

AI agents use restore_backup to create or update resources in Storage — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Storage environment.

WHY IT NEEDS A POLICY

Why restore_backup needs a policy

Restoring a backup writes data to a target environment, potentially overwriting existing data on Compute Instances or Disks. While it could be considered destructive if it overwrites existing data, restores are generally intended to be recovery operations that create or overwrite resources in a controlled way.

From the tool's definition 'Restores a Backup resource to a target environment' — restore operation writes/overwrites data in the target environment for Compute Instances and Disks

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

restore_backup Rate-limited

restore_backup stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "restore_backup": {
      "limits": [
        {
          "counter": "restore_backup_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Storage, so you can run agents against it safely.

FAQ

Questions about restore_backup

What does the restore_backup tool do? +

Restores a Backup resource to a target environment. Supports Compute Instances and Disks. It is categorised as a Write tool in the Storage MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on restore_backup? +

Register the Storage MCP server in PolicyLayer and add a rule for restore_backup: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Storage. Nothing to install.

What risk level is restore_backup? +

restore_backup is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit restore_backup? +

Yes. Add a rate_limit block to the restore_backup rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block restore_backup completely? +

Set action: deny in the PolicyLayer policy for restore_backup. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides restore_backup? +

restore_backup is provided by the Storage MCP server (@google-cloud/storage-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.