ableton-mcp

by ok2ju

Overview Schema Source Related Servers Discussions Admin

Python

Local

set_tempo

Sets the song tempo in BPM (20–999) for Ableton Live sessions so users can control playback speed.

Instructions

Set the song tempo in BPM (20-999).

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": {
      "bpm": "<bpm>"
    },
    "name": "set_tempo"
  }
}

Input Schema

Name	Required	Description	Default
`bpm`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.5.0Nov 6, 2026

TDQS

A3.7/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the mutation/safety profile is covered structurally. The description adds genuinely useful behavioral context by disclosing the accepted range (20-999), implying out-of-range values are rejected. It says nothing about whether the change is undoable, whether it affects playback immediately, or whether tempo is global vs project-scoped.

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?

One short sentence with the action front-loaded and the constraint appended. Nothing is redundant and nothing needs trimming.

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 setter with annotations covering the safety profile and no output schema to explain, this is nearly sufficient: action, unit, and range are all present. Only secondary details (undo behavior, immediate effect on playback, scope) are absent, which is minor at this complexity.

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?

Schema coverage is 0% and the single property is documented only as a bare "number" titled "Bpm", so the description must carry the semantics. It does: it supplies the unit (BPM) and the accepted bounds (20-999), which is exactly the meaning an agent needs to form a valid call.

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 specific verb and resource ("Set the song tempo") plus the unit and valid range, which makes it clearly distinct from siblings like set_scale or set_track_mix. It does not explicitly name an alternative, but the resource is unambiguous.

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

Usage Guidelines3/5

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

Usage is only implied: the agent can infer this is the tool for changing global tempo rather than a track or device setting. There is no explicit when-to-use statement, no mention of prerequisites, and no routing to a sibling for per-track or relative tempo changes.

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