constraint_funnel · Constraint MCP: Risk & Policy

WHAT IT DOES

What constraint_funnel does on Constraint

AI agents invoke constraint_funnel to trigger actions in Constraint. 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 constraint_funnel needs a policy

This tool executes a constraint-based audio transformation operation whose effects depend on supplied arguments (target pitch, intensity/gravity parameters). While not destructive or financial, it triggers external computation that modifies audio state in a manner that cannot be undone without re-rendering.

From the tool's definition Tool description states 'Apply gravitational funnel pull toward a target pitch' which indicates execution of audio processing algorithms that transform or manipulate pitch in real-time based on parameters.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

constraint_funnel Rate-limited

constraint_funnel 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": {
    "constraint_funnel": {
      "limits": [
        {
          "counter": "constraint_funnel_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 Constraint, so you can run agents against it safely.

FAQ

Questions about constraint_funnel

What does the constraint_funnel tool do? +

Apply gravitational funnel pull toward a target pitch. It is categorised as a Execute tool in the Constraint MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on constraint_funnel? +

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

What risk level is constraint_funnel? +

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

Can I rate-limit constraint_funnel? +

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

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

constraint_funnel is provided by the Constraint MCP server (superinstance/constraint-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.