@jam-jam/convert-mcp

Change a notebook song

jj_update_song

Updates selected fields of one notebook song, erases values set to null, and sets complete playlist membership or publish status. Omit fields to leave them unchanged.

Instructions

Changes some fields of one song of the calling account's notebook. Only the fields you pass move; a field set to null erases its value. key is the DISPLAYED key ("G", "Am"). playlistIds is the complete target membership, so it is idempotent. publish: true puts the song on the account's public profile and requires publishDeclaration the first time, plus a public username; publish: false removes it and has no conditions. Publishing is a deliberate act by the account holder: never publish unless they asked. To rewrite lyrics, chords or structure, use jj_create_song with the song's id instead.

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": {
      "songId": "<songId>"
    },
    "name": "jj_update_song"
  }
}

Input Schema

Name	Required	Description
`bpm`	No	Tempo; null erases it.
`key`	No	Displayed key ("G", "Am"); null erases it.
`capo`	No	Capo fret; null erases it.
`title`	No	New title.
`artist`	No	New artist; null erases it.
`songId`	Yes	Stable notebook song id, as returned by jj_list_songs or jj_get_song.
`ifMatch`	No	The `updatedAt` you last read for this object. When set, the write is refused with a conflict error if anything changed it since (another device, or the Jam Jam app). Without it, last writer wins. Use it whenever you read, decided, then write.
`publish`	No	true publishes on the public profile, false un-publishes. Ask the person first.
`playlistIds`	No	COMPLETE target state of playlist membership, not a delta: the song joins the playlists listed and LEAVES every other one. [] removes it from all of them. Omit to leave memberships untouched.
`publishDeclaration`	No	Rights declaration, required ONCE per object the first time it is published. "created": the account holder wrote it. "imported_no_known_restriction": a cover they know of no restriction on. "arrangement": their own arrangement. This is a statement made by the person, not by you: ask them which one applies, never pick one on their behalf.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.2Nov 13, 2026

TDQS

A4.6/5.0

Behavior5/5

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

With no annotations, the description carries the full burden and does so: partial-update semantics, null as an eraser, playlistIds being idempotent full-replacement rather than a delta, the one-time publishDeclaration requirement plus public-username precondition, and a policy constraint against unprompted publishing. These are exactly the destructive and preconditional behaviors an agent could otherwise get wrong.

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?

Front-loaded with the core patch semantics and null-erasure rule, then layered parameter notes, then the alternative. Dense and mostly waste-free, though a few clauses re-encode what the schema already says, which is mild redundancy for a ten-parameter tool.

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

Completeness5/5

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

For a ten-parameter mutation tool with no output schema and no annotations, the definition covers the destructive edge cases, idempotency, publish preconditions, and the sibling alternative. An agent has enough to decide whether to call it and how, without guessing.

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 description coverage is 100%, so every parameter is already documented in structured form; the prose largely restates those descriptions (displayed key format, playlistIds as complete state, publish meaning). The one genuinely additive framing is calling out idempotency explicitly, but the baseline of 3 applies when the schema does the heavy lifting.

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 and resource ('Changes some fields of one song of the calling account's notebook') with explicit scope, and separates itself from the sibling that rewrites content by naming jj_create_song. An agent can distinguish this from jj_create_song or jj_update_playlist without opening any schema.

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

Usage Guidelines5/5

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

Gives an explicit routing rule ('To rewrite lyrics, chords or structure, use jj_create_song with the song's id instead') plus a hard exclusion on publishing ('never publish unless they asked') and the preconditions for publish/unpublish. When-to-use, when-not-to-use and the alternative are all present.

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