X32/M32 MCP Server

Set Channel Fader Volume

channel_set_volume

Idempotent

Set the volume of any X32/M32 input channel via fader level, using linear (0.0–1.0) or dB (-90 to +10) units. Unity is 0 dB or 0.75 linear for calibration.

Instructions

Set the fader level (volume) for a specific input channel on the X32/M32 mixer. Supports both linear values (0.0-1.0) and decibel values (-90 to +10 dB). Unity gain is 0 dB or 0.75 linear.

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": {
      "channel": "<channel>",
      "value": "<value>"
    },
    "name": "channel_set_volume"
  }
}

Input Schema

Name	Required	Description	Default
`unit`	No	Unit of the value: "linear" (0.0-1.0) or "db" (-90 to +10 dB). Default is "linear".	linear
`value`	Yes	Volume value (interpretation depends on unit parameter)
`channel`	Yes	Input channel number from 1 to 32

Schema Changelog

Changes observed during successful MCP inspections.

First observedv3.2.0Aug 9, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already indicate readOnlyHint=false, idempotentHint=true, and destructiveHint=false, setting the bar lower. The description adds valuable behavioral context beyond annotations, including the accepted value ranges and the linear/dB conversion relationship (e.g., unity gain at 0 dB or 0.75 linear). It does not contradict any annotation and does not need to discuss destructive behavior since it's already marked non-destructive.

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 two sentences long and front-loaded with the core action. It provides essential information (units, ranges, unity gain) without any redundancy or filler. Every sentence contributes value, making it highly concise and well-structured.

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

Completeness4/5

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

Given the simple setter nature of the tool and the absence of an output schema, the description covers the essential aspects: what is set, on which channel, and with what units. It does not explain return values, but for a setter that is typically not critical. The description also omits edge-case behavior (e.g., clamping out-of-range values), but this is a minor gap given the schema already specifies min/max. Overall, it is sufficiently complete for an agent to use the tool effectively.

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

Parameters4/5

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

The schema already provides 100% coverage of all three parameters, so the baseline is 3. The description adds meaningful semantic information about the relationship between the 'value' and 'unit' parameters, particularly the linear/dB ranges and unity gain equivalence. This goes beyond the schema's descriptions, enhancing the agent's understanding of valid inputs.

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 function: 'Set the fader level (volume) for a specific input channel on the X32/M32 mixer.' It uses a specific verb and resource, and distinguishes this tool from siblings like channel_set_gain (which controls trim/gain, not fader) and bus_set_volume/main_set_volume (which target different channel types).

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 clearly implies this is for input channels only ('specific input channel'), which differentiates it from bus/main volume tools. It also mentions the supported units and unity gain, providing context for when to use each. However, it does not explicitly state when not to use it or name alternative tools, so it stops short of full exclusionary guidance.

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