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Aseprite MCP

by MalloyTheDev
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dither_band

Dithers the boundary between two adjacent palette ramp steps, adding an apparent extra shade to widen the transition between two colors in a pixel-art sprite.

Instructions

Dither the boundary between two adjacent ramp steps, widening the transition.

Dithering in pixel art is a limited-palette necessity rather than a style: it buys
an apparent extra shade between two you already have. It reads as dated when applied
globally, which is why this is scoped to one boundary rather than offered as a
filter over the whole sprite.

Args:
    ramp: Colours darkest first.
    from_step, to_step: 1-based indices into `ramp`, and they must be adjacent.
        Dithering between distant steps produces visible noise, not a gradient.
        **1-based, while `ramp` is a list the caller indexes from 0**, so the pair
        that dithers `ramp[3]` against `ramp[4]` is `from_step=4, to_step=5`. The two
        conventions usually sit a line apart:

            shade_region_by_light(f, GOLD, base_color=GOLD[4], ...)
            dither_band(f, GOLD, from_step=5, to_step=6, ...)   # GOLD[4], GOLD[5]

        Off by one still names an adjacent pair, so the call succeeds and dithers the
        wrong boundary. The result reports `from_color` and `to_color` for that
        reason: it is the only way to check the intent from the output.
    pattern: "bayer4" (finest, the usual choice), "bayer2" (chunkier) or "checker"
        (a hard 50/50 that suits a sharp material change).
    width: How far the dithered zone reaches into each band, in pixels. This is what
        widens the transition, which is the point of dithering: at width=1 only the
        seam itself alternates, and every pattern collapses to the same result
        because a one-pixel-deep band can only alternate.
    tolerance: How close a pixel must be to one of the two colours to take part.
    layer: Target layer (default: top layer).
    frame: Target frame, 1-based.

Only pixels of the two named colours that border each other are touched, so the
rest of the sprite is untouched even where it uses the same ramp.

Returns `dithered_pixels`, and `from_color`/`to_color`, the two colours the steps
actually resolved to.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
rampYes
frameNoDefault: 1.
layerNo
widthNoDefault: 2.
patternNoDefault: "bayer4".bayer4
to_stepYes
filenameYes
from_stepYes
toleranceNoDefault: 24.0.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Addedv0.10.0

TDQS

A4.5/5.0
Behavior4/5

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

Annotations only supply readOnlyHint=false and openWorldHint=false, so the description carries most of the burden and does so well: it discloses that only pixels of the two named colours that border each other are touched, that the rest of the sprite is untouched, and that the result reports from_color/to_color. It does not explicitly state persistence/undo behavior, which keeps it from a 5.

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 purpose, then organized into a rationale block and an Args block. The indexing explanation is lengthy but earns its place given the documented off-by-one hazard. Slightly verbose, but no clearly wasted sentence.

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 9-parameter mutation tool with no output schema and low schema coverage, the description supplies the missing behavioural and parameter context, including return fields, scope of effect, and the indexing convention. Nothing an agent needs to invoke it correctly appears to be missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 44%, yet the description documents nearly every parameter with meaning beyond the schema: 1-based from_step/to_step semantics with a worked off-by-one example, the three pattern choices and their trade-offs, width's effect (and that width=1 collapses all patterns), tolerance, layer and frame. This fully compensates for the sparse schema.

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 (dither) and resource (the boundary between two adjacent ramp steps) plus the effect (widening the transition). It is immediately distinguishable from ramp-generation siblings like generate_ramp/ramp_between and from shade_region_by_light, which the description itself contrasts against.

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?

Explains the context for use (limited-palette necessity, buys an extra apparent shade) and why it is deliberately scoped to one boundary rather than a global filter. It also states the adjacency constraint. However, it never explicitly routes the agent to a named alternative tool for the global case, so it stops just short of a 5.

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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