fix_loop · Mcp Flow MCP: Risk & Policy

WHAT IT DOES

What fix_loop does on Mcp Flow

AI agents invoke fix_loop to trigger actions in Mcp Flow. 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 fix_loop needs a policy

This tool triggers a complex automation loop that runs project checks (equivalent to executing tests/verification commands), analyzes outputs, and applies patches to code. While the modifications are theoretically reversible (patches can be undone), the tool actively executes external operations and modifies the codebase based on dynamic analysis results, making it Execute rather than Write.

From the tool's definition fix_loop runs an iterative 'verify→analyze→fix loop' that executes code checks, analyses failures, and generates/applies patches. This involves running external commands (project checks), processing results, and applying code modifications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fix_loop Rate-limited

fix_loop 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": {
    "fix_loop": {
      "limits": [
        {
          "counter": "fix_loop_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 Mcp Flow, so you can run agents against it safely.

FAQ

Questions about fix_loop

What does the fix_loop tool do? +

Run a controlled verify→analyze→fix loop. Each iteration runs the. It is categorised as a Execute tool in the Mcp Flow MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on fix_loop? +

Register the Mcp Flow MCP server in PolicyLayer and add a rule for fix_loop: 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 Flow. Nothing to install.

What risk level is fix_loop? +

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

Can I rate-limit fix_loop? +

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

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

fix_loop is provided by the Mcp Flow MCP server (remimenguy/mcp-flow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.