save_code_pattern · Handoff MCP: Risk & Policy

WHAT IT DOES

What save_code_pattern does on Handoff

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

WHY IT NEEDS A POLICY

Why save_code_pattern needs a policy

This tool creates or modifies stored code patterns in a shared memory hub. While it does not delete data (Destructive) or execute code (Execute), it persists new or updated pattern information that agents can retrieve.

From the tool's definition The tool name includes the verb 'save' and the description explicitly states 'Save a reusable code pattern or template', indicating data creation or modification.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

save_code_pattern Rate-limited

save_code_pattern 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": {
    "save_code_pattern": {
      "limits": [
        {
          "counter": "save_code_pattern_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 Handoff, so you can run agents against it safely.

FAQ

Questions about save_code_pattern

What does the save_code_pattern tool do? +

Save a reusable code pattern or template (e.g. JWT interceptor, FCM handler, error boundaries). It is categorised as a Write tool in the Handoff MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on save_code_pattern? +

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

What risk level is save_code_pattern? +

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

Can I rate-limit save_code_pattern? +

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

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

save_code_pattern is provided by the Handoff MCP server (juan-severiano/handoff-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.