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export_onion_skin

Destructive

Export a frame with neighboring frames ghosted behind it to create onion-skin reference PNGs for animation review and comparison.

Instructions

Export a frame with neighbouring frames ghosted behind it (onion skin).

Args:
    frame: The in-focus frame (drawn fully opaque), 1-based.
    previous, next: How many earlier/later frames to ghost.
    ghost_opacity: Max opacity (0-255) of the nearest ghost; further frames fade.
    scale: Integer upscaling factor for the output PNG.
    overwrite: Replace `output` if it already exists (default False = no-clobber).

Input Schema

TableJSON Schema

Name	Required	Description
`next`	No	Default: 0.
`frame`	Yes
`scale`	No	Default: 4.
`output`	Yes
`filename`	Yes
`previous`	No	Default: 2.
`overwrite`	No	Default: false.
`ghost_opacity`	No	Default: 80.

Schema Changelog

Changes observed during successful MCP inspections.

Changed13 schema fields changedv0.10.0Oct 4, 2026
- removedInput schema / properties / filename / title
```
Removed value: -"Filename"
```
- removedInput schema / properties / frame / title
```
Removed value: -"Frame"
```
- addedInput schema / properties / ghost_opacity / description
```
Added value: +"Default: 80."
```
- removedInput schema / properties / ghost_opacity / title
```
Removed value: -"Ghost Opacity"
```
- addedInput schema / properties / next / description
```
Added value: +"Default: 0."
```
- removedInput schema / properties / next / title
```
Removed value: -"Next"
```
- removedInput schema / properties / output / title
```
Removed value: -"Output"
```
- addedInput schema / properties / overwrite
```
Added value: +{
+  "default": false,
+  "description": "Default: false.",
+  "type": "boolean"
+}
```
- addedInput schema / properties / previous / description
```
Added value: +"Default: 2."
```
- removedInput schema / properties / previous / title
```
Removed value: -"Previous"
```
- addedInput schema / properties / scale / description
```
Added value: +"Default: 4."
```
- removedInput schema / properties / scale / title
```
Removed value: -"Scale"
```
- removedInput schema / title
```
Removed value: -"export_onion_skinArguments"
```
First observedv0.7.0Jul 29, 2026

TDQS

A3.8/5.0

Behavior3/5

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

Annotations already flag the tool as a non-read-only, destructive write (destructiveHint=true), so the no-clobber behaviour needs credit only for the added detail: 'overwrite: Replace output if it already exists (default False = no-clobber)'. That is a genuinely useful behavioural fact beyond the annotation. However, other behaviours an agent needs—output format/bit depth beyond PNG, failure behaviour when the frame is out of range, and whether neighbouring frames are silently clipped at sequence bounds—are absent.

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?

The front-loaded one-sentence summary is strong and the per-argument list is tight; each line earns its place. The Google-style 'Args:' block formatting is slightly awkward embedded in a description field but does not waste words.

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

Completeness3/5

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

For an 8-parameter destructive export with no output schema, the description covers the fusion/ghost semantics and the clobber flag but leaves filename/output semantics and error/boundary behaviour unspecified. Adequate, not complete."

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?

At 63% schema coverage, several params carry only a 'Default: N' stub. The description compensates well for the semantically important ones: frame is 'the in-focus frame (drawn fully opaque), 1-based', previous/next are 'how many earlier/later frames to ghost', ghost_opacity is 'max opacity (0-255) of the nearest ghost; further frames fade', and scale is 'integer upscaling factor'. The 1-based indexing and fade semantics are real added meaning. Only filename and output remain unexplained.

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 (export) and resource (a frame with ghosted neighbouring frames), and the parenthetical '(onion skin)' names the exact technique. Among a large set of export_* siblings, this is clearly distinguishable as the onion-skin renderer.

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?

The description implies usage by defining what onion skinning is, but never states when to choose this over the neighbouring export_frames, export_layer, or render_preview siblings, nor any prerequisite. Usage is inferred from the technique name rather than guided.

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

Deploy Server

export_onion_skin

Instructions

Input Schema

Schema Changelog

TDQS

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