Skip to main content
Glama
MalloyTheDev

Aseprite MCP

by MalloyTheDev
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Local

build_asset_from_spec

Destructive

Build an Aseprite asset from a validated spec document: scaffolds sprite, applies layers, animation, slices, and exports. Structure only; no pixels drawn.

Instructions

Build the asset described by an aseprite_mcp.asset_spec.v1 document.

Executes the (validated) plan by dispatching each step to an existing tool: scaffolds
the sprite for its `kind`, applies palette / extra layers / animation frames+tags /
slices, and runs the requested exports. **Structure only - no pixels are drawn;** the
returned manifest's `suggested_next_actions` hand the actual art back to you.

Args:
    overwrite: Passed to the export steps (replace existing export files). The sprite
        itself is created no-clobber, so building over an existing ``<name>.aseprite``
        raises - build to a new name or remove the old file.

Returns a ``workflow_manifest.v1`` (kind ``asset_spec``) with the created files, the
executed `plan`, and next actions. Raises ``ValidationFailed`` if the spec is invalid.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
specYes
overwriteNoDefault: false.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed4 schema fields changedv0.10.0
    • addedInput schema / properties / overwrite / description
      Added value: +"Default: false."
    • removedInput schema / properties / overwrite / title
      Removed value: -"Overwrite"
    • removedInput schema / properties / spec / title
      Removed value: -"Spec"
    • removedInput schema / title
      Removed value: -"build_asset_from_specArguments"
  2. First observedv0.7.0

TDQS

A4.2/5.0
Behavior4/5

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

Annotations declare destructiveHint=true, and the description openly explains that the sprite itself is created no-clobber (raises on existing <name>.aseprite) while overwrite only affects export files. This is exactly the kind of nuance annotations alone cannot convey, though it doesn't cover all mutation boundaries or return format details in full.

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?

It is appropriately sized and front-loaded: a one-sentence summary, then a paragraph explaining execution flow, then Args and Returns sections. Every sentence carries information and nothing is redundant.

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?

Given no output schema, the description appropriately explains the return type (workflow_manifest.v1) and its contents. It covers the no-clobber behavior, the validation failure mode, and the suggested_next_actions mechanism. It could be slightly more complete by mentioning any constraints on the spec format or typical failure modes, but it is adequate for a complex orchestrator tool.

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?

The spec param is a nested object with no schema description, but the description explains its role (drives scaffolding, palette, layers, animation, exports) and references a versioned document type. The overwrite parameter gets a full behavioral explanation (passed to export steps, no-clobber for sprite creation) that goes beyond the schema's 'Default: false.' This adds substantial meaning despite 50% schema coverage.

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?

The description states a specific verb and resource: 'Build the asset described by a aseprite_mcp.asset_spec.v1 document.' It clearly identifies itself as a high-level orchestrator that dispatches to existing tools, distinguishing it from atomic siblings like draw_pixels or export_png. An agent can tell this composes a batch of operations based on a spec.

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?

Usage is implied by the description's emphasis on executing a validated plan and handing art back via suggested_next_actions, but it does not explicitly state when to use this vs plan_asset_spec or validate_asset_spec (siblings in the list). The overwrite arg behavior is explained, but there are no explicit when/when-not/alternatives statements.

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

Deploy Server

Other Tools