PostFader V12 — FL Studio MCP Server

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piano_roll_transform_notes

Destructive

Edit existing piano-roll notes by quantizing, transposing, humanizing, duplicating, deleting, or clearing selected notes or all notes in one channel pattern.

Instructions

Quantize, transpose, humanize, duplicate, delete, or clear existing notes.

Applies to the selected notes or the whole score of one channel in one
pattern. Requires write mode and the one-time piano_roll_setup; read the
notes first with piano_roll_read_notes. delete and clear remove notes in
scope. Works like piano_roll_write_notes: a dispatch is not proof, so
inspect the evidence. Use piano_roll_write_notes to add new notes.

Input Schema

TableJSON Schema

Name	Required	Description
`request`	Yes	Operation (quantize, transpose, humanize, duplicate, delete, or clear), scope (selected or all), and its settings.
`auto_trigger`	No	Select the target and run the script automatically; false leaves both to the user.
`channel_index`	Yes	Global Channel Rack index from channel_list.
`pattern_number`	Yes	Pattern whose score to open; selected before the script runs.

Output Schema

TableJSON Schema

Name	Required	Default
`mode`	No
`status`	Yes
`target`	No
`trigger`	No
`warnings`	No
`operation`	Yes
`request_id`	Yes
`script_path`	Yes
`requested_at`	Yes
`project_saved`	No
`script_sha256`	Yes
`schema_version`	No	1.0
`verification_target`	No
`application_verified`	No
`requested_note_count`	No
`verification_trigger`	No
`requested_note_digest`	No
`script_runtime_evidence`	No
`verification_script_sha256`	No
`authoritative_note_readback_available`	No

Schema Changelog

Changes observed during successful MCP inspections.

Addedv11.0.2Oct 5, 2026

TDQS

A4.7/5.0

Behavior5/5

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

Beyond the annotations (destructiveHint=true, idempotentHint=false, readOnlyHint=false), the description adds the write-mode requirement, the one-time setup dependency, the fact that delete/clear remove notes in scope, and a non-obvious caveat that 'a dispatch is not proof, so inspect the evidence'. This is rich behavioral context that the structured fields do not supply.

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?

Front-loaded with the operation list, followed by scope, prerequisites, the destructive caveat, and the sibling routing note. Every sentence carries distinct, load-bearing information with no repetition or padding.

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?

With an output schema present the description need not explain return values, and annotations already encode the safety profile. The description still supplies the missing operational context (write mode, setup, read-first, scope, sibling alternatives), so nothing an agent needs to invoke this correctly is absent.

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 the baseline is 3. The description enumerates the operation choices and mentions the selected/all scope, but adds no meaning beyond the schema enums for those, and says nothing about semitones, grid_beats, timing_beats, velocity_amount, repeats, seed, or quantize_lengths. The schema carries the parameter semantics.

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 specific verbs (quantize, transpose, humanize, duplicate, delete, clear) acting on 'existing notes', and explicitly distinguishes itself from the sibling piano_roll_write_notes ('Use piano_roll_write_notes to add new notes'). An agent can differentiate this from its siblings 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 explicit prerequisites ('Requires write mode and the one-time piano_roll_setup'), a required prior step ('read the notes first with piano_roll_read_notes'), scope semantics ('selected notes or the whole score of one channel in one pattern'), and names the alternative tool for a different task. When/when-not and alternatives are all covered.

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

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