create_sandbox · E2b MCP: Risk & Policy

WHAT IT DOES

What create_sandbox does on E2b

AI agents invoke create_sandbox to trigger actions in E2b. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why create_sandbox needs a policy

Creating a sandbox spins up an external compute resource (a live, isolated environment) that can subsequently run arbitrary code. This is an external operation with real resource consumption and side effects beyond simple data creation, placing it in Execute. Misuse could lead to resource exhaustion, unauthorized compute usage, or provision of an environment for malicious code execution, warranting high severity.

From the tool's definition "Create a new E2B sandbox" — instantiates an isolated execution environment; part of a server whose purpose is to "execute code securely in isolated E2B sandboxes"

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_sandbox Rate-limited

create_sandbox stays usable, but rate-capped — a runaway agent can't fire it dozens of times 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_sandbox": {
      "limits": [
        {
          "counter": "create_sandbox_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches E2b, so you can run agents against it safely.

FAQ

Questions about create_sandbox

What does the create_sandbox tool do? +

Create a new E2B sandbox. It is categorised as a Execute tool in the E2b MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on create_sandbox? +

Register the E2b MCP server in PolicyLayer and add a rule for create_sandbox: 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 E2b. Nothing to install.

What risk level is create_sandbox? +

create_sandbox is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit create_sandbox? +

Yes. Add a rate_limit block to the create_sandbox 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_sandbox completely? +

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

create_sandbox is provided by the E2b MCP server (yukkit/e2b-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.