AI agents use set_param to create or update resources in Pure Data MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Pure Data MCP Server environment.
The tool creates or modifies data reversibly within a Pure Data patch (parameter adjustment). While it affects a live DSP environment, the modification is not destructive (parameters can be changed again or reverted), and there is no data deletion, financial transaction, or arbitrary code execution.
From the tool's definition Tool description states 'Modify a parameter of an existing Pd object' — a clear modification action on live audio/DSP state without deletion.
Documented attack patterns abuse exactly the kind of access set_param gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Pure Data MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for set_param:
{
"version": "1",
"default": "deny",
"tools": {
"set_param": {
"limits": [
{
"counter": "set_param_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}set_param 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.
Free to start. No card required.
Modify a parameter of an existing Pd object. It is categorised as a Write tool in the Pure Data MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Pure Data MCP Server MCP server in PolicyLayer and add a rule for set_param: 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 Pure Data MCP Server. Nothing to install.
set_param is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the set_param 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.
Set action: deny in the PolicyLayer policy for set_param. 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.
set_param is provided by the Pure Data MCP Server MCP server (nikmaniatis/pd-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Pure Data MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
11 Pure Data MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.