@jam-jam/convert-mcp

Mastering: limits, setting ranges, targets and render quota

jj_mastering_capabilities

Reports the live Mastering engine contract: module units, ranges, steps and neutral values, loudness targets, built-in presets, size and preset limits, plus render permission and quota. Call it before creating a preset or mastering audio.

Instructions

Reports the live contract of the Mastering engine (GET /mastering/capabilities): for each of the eight modules the unit, range, step, neutral and initial value, the loudness targets, the built-in presets (builtin:balanced, ... with their full settings, a good starting point for a new preset), the limits (200 MB, 10 minutes, 50 presets of 60 characters), the validation tolerance, whether THIS account may render through the API (renderAllowed: any account with mastering:write) and the render quota balance. Call it before jj_create_mastering_preset or jj_master_audio with inline settings. Needs no scope and costs nothing.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "jj_mastering_capabilities"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.2Nov 13, 2026

TDQS

A3.9/5.0

Behavior3/5

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

With no annotations present, the description does meaningful work: it declares the operation reads live server state, requires no scope, and costs nothing, and it calls out the account-specific `renderAllowed` flag gated on mastering:write plus the render quota balance. What it omits is response shape/caching behavior and how the embedded built-in preset settings are structured, so an agent still can't predict the payload's organization — solid but not complete for an annotation-free tool.

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

Conciseness4/5

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

A single dense sentence plus one short guidance sentence, front-loaded with the operation and its response contents, ending with the actionable 'call it before X'. The long enumeration of limits (200 MB, 10 minutes, 50 presets of 60 characters) is arguably payload detail that could be trimmed, but it is packed rather than padded.

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?

There is no output schema, so the description must convey return values — and it does so thoroughly across modules, targets, presets, limits, permissions and quota. The remaining gap is structural: it doesn't indicate nesting or how to address a specific module's fields, which matters for a contract object this large.

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?

The tool takes zero parameters, so the baseline is 4, but the description spends its detail describing outputs rather than confirming the no-argument calling convention. It never explicitly says 'call with no arguments', which would be the one parameter-semantic fact worth stating for a zero-param tool.

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?

States a specific verb ('Reports') and a precise resource ('the live contract of the Mastering engine', with the GET endpoint), then enumerates exactly what that contract contains: per-module unit/range/step/neutral/initial values, loudness targets, built-in presets, limits, tolerance, renderAllowed and quota balance. This is unambiguous and clearly distinct from sibling read tools like jj_list_mastering_presets (which lists user presets) or jj_stems_capabilities (a different engine's contract).

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 explicit timing: 'Call it before jj_create_mastering_preset or jj_master_audio with inline settings', naming the concrete downstream tools and the condition (inline settings) that triggers the need. That qualifier implicitly scopes out cases where settings aren't supplied inline, but the tool never states an outright when-not or an alternative source of this information, so it falls short of a full 5.

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