create_bucket · MinIO Storage MCP: Risk & Policy

WHAT IT DOES

What create_bucket does on MinIO Storage MCP

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

WHY IT NEEDS A POLICY

Why create_bucket needs a policy

Creating a bucket is a Write operation as it creates new data structures (buckets) in the storage system. It is reversible since buckets can be deleted via the sibling 'delete_bucket' tool. Severity is medium because while bucket creation has limited blast radius and is reversible, improper bucket creation could consume resources, create unintended storage structures, or interfere with application workflows.

From the tool's definition Tool name 'create_bucket' with description '创建存储桶' (Chinese: 'create bucket') explicitly creates new storage buckets in MinIO object storage. This is a reversible write operation that creates a new resource.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_bucket Rate-limited

create_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": {
    "create_bucket": {
      "limits": [
        {
          "counter": "create_bucket_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 MinIO Storage MCP, so you can run agents against it safely.

FAQ

Questions about create_bucket

What does the create_bucket tool do? +

创建存储桶. It is categorised as a Write tool in the MinIO Storage MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_bucket? +

Register the MinIO Storage MCP server in PolicyLayer and add a rule for create_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 Storage MCP. Nothing to install.

What risk level is create_bucket? +

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

Can I rate-limit create_bucket? +

Yes. Add a rate_limit block to the create_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 create_bucket completely? +

Set action: deny in the PolicyLayer policy for create_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 create_bucket? +

create_bucket is provided by the MinIO Storage MCP server (pickstar-2002/minio-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.