PureData-MCP

Send Pure Data Control Message

pd_send_control

Send raw control messages to a live Pure Data patch bus for real-time parameter tweaks, without rebuilding the canvas.

Instructions

Send a safe raw control message to the running live patch control bus for parameter tweaks without rebuilding the canvas.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "selector": "<selector>"
    },
    "name": "pd_send_control"
  }
}

Input Schema

Name	Required	Description	Default
`args`	No
`selector`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.2Aug 8, 2026

TDQS

B3.3/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must disclose behavior. It claims the message is 'safe' and that it works 'without rebuilding the canvas,' but it doesn't explain what 'safe' means, whether it can crash the patch, what happens with invalid messages, or any side effects on the running state. This is a significant gap for a tool sending raw control messages.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, compact sentence starting with the core verb 'Send' and resource. Every word adds value, with no filler or repetition. It is appropriately front-loaded and concise.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simple schema but no annotations and no output schema, the description needs to provide enough context for an agent to invoke the tool correctly. It omits parameter semantics, error handling, and clear differentiation from pd_set_params, leaving the agent under-informed for a tool that sends raw messages to a live patch.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the description gives no explanation of 'selector' or 'args.' The agent must infer that 'selector' is the message name and 'args' its arguments, but no semantics or format hints are provided. The description completely fails to compensate for the schema gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose with a specific verb 'Send' and a specific resource: 'safe raw control message' to the 'running live patch control bus' for 'parameter tweaks without rebuilding the canvas.' This distinguishes it from higher-level siblings like pd_set_params, making the purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear usage context: 'for parameter tweaks without rebuilding the canvas' implies this is for fine-tuning a running patch rather than structural edits. However, it doesn't explicitly name alternatives or state when not to use the tool, so it lacks explicit exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.