storage_copy_object · Google Cloud MCP: Risk & Policy

WHAT IT DOES

What storage_copy_object does on Google Cloud

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

WHY IT NEEDS A POLICY

Why storage_copy_object needs a policy

This tool creates or modifies data (copies objects) without permanent deletion. While copying between buckets could affect large volumes of data and incur costs, the operation is reversible (the copy can be deleted). It does not execute arbitrary code, delete irreversibly, or move money, so Write is the appropriate category.

From the tool's definition Tool name 'storage_copy_object' and description 'Copy an object between Cloud Storage buckets' indicate data modification—the tool creates a copy of data in a new location, which is a reversible write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

storage_copy_object Rate-limited

storage_copy_object 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": {
    "storage_copy_object": {
      "limits": [
        {
          "counter": "storage_copy_object_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about storage_copy_object

What does the storage_copy_object tool do? +

Copy an object between Cloud Storage buckets. It is categorised as a Write tool in the Google Cloud MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on storage_copy_object? +

Register the Google Cloud MCP server in PolicyLayer and add a rule for storage_copy_object: 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 Google Cloud. Nothing to install.

What risk level is storage_copy_object? +

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

Can I rate-limit storage_copy_object? +

Yes. Add a rate_limit block to the storage_copy_object 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 storage_copy_object completely? +

Set action: deny in the PolicyLayer policy for storage_copy_object. 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 storage_copy_object? +

storage_copy_object is provided by the Google Cloud MCP server (lockon-n/google-cloud-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.