update_policy · Privy MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_policy does on Privy MCP Server

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

WHY IT NEEDS A POLICY

Why update_policy needs a policy

This tool modifies policy configurations that govern blockchain operations and transaction signing permissions. While the change is reversible (Write rather than Destructive), a misconfigured policy update could broadly expand access to sensitive wallet operations or weaken security controls.

From the tool's definition Tool description states 'Updates an existing policy' which modifies existing data. In the context of a blockchain wallet management system (Privy), policies control access and authorization rules for wallet operations, transaction signing, and fund movement.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_policy Rate-limited

update_policy 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": {
    "update_policy": {
      "limits": [
        {
          "counter": "update_policy_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 Privy MCP Server, so you can run agents against it safely.

FAQ

Questions about update_policy

What does the update_policy tool do? +

Updates an existing policy by its ID. It is categorised as a Write tool in the Privy 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 update_policy? +

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

What risk level is update_policy? +

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

Can I rate-limit update_policy? +

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

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

update_policy is provided by the Privy MCP Server MCP server (privy-io/privy-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.