modularsynth-mcp

by gregorybruneau

Overview Schema Source Related Servers Discussions Admin

JavaScript

Local

Set transport

set_transport

Starts or stops all clocks in a patch to run sequencers or halt a playing song.

Instructions

Start or stop every Clock in the patch (the ▶/■ button): sequencers play while it runs. Stopping also stops a playing song.

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": {
      "running": "<running>"
    },
    "name": "set_transport"
  }
}

Input Schema

Name	Required	Description	Default
`running`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.3.1Nov 2, 2026

TDQS

A3.8/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description usefully adds the side effect that stopping halts a playing song and that the tool acts on all Clocks globally, but says nothing about idempotency, error behavior if already in that state, or whether state persists.

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?

A single compact sentence pair with the action and target front-loaded, followed by the relevant side effect. No filler, and the UI glyph gives an extra anchor for free.

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?

For a one-parameter transport toggle with annotations and no output schema, the description covers the operation, scope (every Clock), and the notable consequence on song playback. Minor gaps remain around return value and restart semantics, but nothing blocking.

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

Parameters3/5

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

Schema coverage is 0% for the single `running` boolean, but the description's 'Start or stop' makes the true/false mapping self-evident. Baseline 3 is appropriate since the semantics are obvious even without explicit schema documentation.

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

Purpose4/5

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

States a concrete verb pair (start/stop) and the target resource (every Clock in the patch), plus the UI metaphor (▶/■) that removes ambiguity. It is distinguishable from play_song/play_notes, though the relationship is only hinted at by the closing clause rather than spelled out.

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?

Gives clear operating context: sequencers play while transport runs, and stopping also halts a playing song. There is no explicit when-not or named alternative (e.g., play_song for song playback), so the agent must infer the boundary.

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