set_parameter · Touchdesigner MCP: Risk & Policy

WHAT IT DOES

What set_parameter does on Touchdesigner

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

WHY IT NEEDS A POLICY

Why set_parameter needs a policy

Setting a parameter is a reversible Write operation—it changes state without deleting data or executing arbitrary code. While it could indirectly affect TouchDesigner's runtime behavior depending on what parameters are modified, the tool itself is fundamentally a configuration setter.

From the tool's definition Tool description: 'Set a parameter on an operator.' This modifies operator parameters in TouchDesigner, which are configuration settings that affect behavior but are reversible.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_parameter Rate-limited

set_parameter 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": {
    "set_parameter": {
      "limits": [
        {
          "counter": "set_parameter_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 Touchdesigner, so you can run agents against it safely.

FAQ

Questions about set_parameter

What does the set_parameter tool do? +

Set a parameter on an operator. It is categorised as a Write tool in the Touchdesigner MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_parameter? +

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

What risk level is set_parameter? +

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

Can I rate-limit set_parameter? +

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

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

set_parameter is provided by the Touchdesigner MCP server (mrinalghosh/touchdesigner-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.