create-wallet · MCP EVM Signer MCP: Risk & Policy

WHAT IT DOES

What create-wallet does on MCP EVM Signer

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

WHY IT NEEDS A POLICY

Why create-wallet needs a policy

This tool creates a new Ethereum wallet (key pair), which is a write operation that generates and stores new cryptographic material locally. It does not move funds or execute transactions, but misuse could lead to untracked wallets or key management issues. Severity is medium because while it doesn't directly move funds, improperly managed wallets created by an AI agent could later be used in financial operations.

From the tool's definition Create a new Ethereum wallet

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create-wallet Rate-limited

create-wallet 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-wallet": {
      "limits": [
        {
          "counter": "create-wallet_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 MCP EVM Signer, so you can run agents against it safely.

FAQ

Questions about create-wallet

What does the create-wallet tool do? +

Create a new Ethereum wallet. It is categorised as a Write tool in the MCP EVM Signer 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-wallet? +

Register the MCP EVM Signer MCP server in PolicyLayer and add a rule for create-wallet: 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 MCP EVM Signer. Nothing to install.

What risk level is create-wallet? +

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

Can I rate-limit create-wallet? +

Yes. Add a rate_limit block to the create-wallet 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-wallet completely? +

Set action: deny in the PolicyLayer policy for create-wallet. 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-wallet? +

create-wallet is provided by the MCP EVM Signer MCP server (zhangzhongnan928/mcp-evm-signer). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.