minio_make_bucket · MinIO MCP Server MCP: Risk & Policy

WHAT IT DOES

What minio_make_bucket does on MinIO MCP Server

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

WHY IT NEEDS A POLICY

Why minio_make_bucket needs a policy

This tool creates a new bucket (a top-level storage container) in MinIO/S3, which is a reversible Write operation. While bucket creation modifies infrastructure, it is not destructive (can be deleted via minio_remove_bucket), does not execute arbitrary code, and does not move money.

From the tool's definition Tool description explicitly states 'Create a new bucket in MinIO'. The action is bucket creation, which modifies the storage system by adding a new container for objects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

minio_make_bucket Rate-limited

minio_make_bucket 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": {
    "minio_make_bucket": {
      "limits": [
        {
          "counter": "minio_make_bucket_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 MinIO MCP Server, so you can run agents against it safely.

FAQ

Questions about minio_make_bucket

What does the minio_make_bucket tool do? +

Create a new bucket in MinIO. It is categorised as a Write tool in the MinIO MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on minio_make_bucket? +

Register the MinIO MCP Server MCP server in PolicyLayer and add a rule for minio_make_bucket: 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 MinIO MCP Server. Nothing to install.

What risk level is minio_make_bucket? +

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

Can I rate-limit minio_make_bucket? +

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

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

minio_make_bucket is provided by the MinIO MCP Server MCP server (raphaelren/minio-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.