register_agent · nullpath MCP Client MCP: Risk & Policy

WHAT IT DOES

What register_agent does on nullpath MCP Client

AI agents use register_agent to commit financial operations through nullpath MCP Client — usually the final step of a payment, billing, or trading workflow. A call moves real money.

WHY IT NEEDS A POLICY

Why register_agent needs a policy

The tool explicitly commits a financial transaction — a $0.10 USDC payment — using a wallet private key. This constitutes a real monetary obligation, placing it in the Financial category. Misuse could drain funds or register unauthorized agents, warranting high severity.

From the tool's definition 'Register a new agent on the marketplace. Requires $0.10 USDC payment. Set NULLPATH_WALLET_KEY env var.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

register_agent Approval-gated

Any call to register_agent is blocked until a human approves it. The rest of the server keeps working.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "register_agent": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

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

FAQ

Questions about register_agent

What does the register_agent tool do? +

Register a new agent on the marketplace. Requires $0.10 USDC payment. Set NULLPATH_WALLET_KEY env var. It is categorised as a Financial tool in the nullpath MCP Client MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on register_agent? +

Register the nullpath MCP Client MCP server in PolicyLayer and add a rule for register_agent: 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 nullpath MCP Client. Nothing to install.

What risk level is register_agent? +

register_agent is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit register_agent? +

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

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

register_agent is provided by the nullpath MCP Client MCP server (nullpath-labs/mcp-client). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.