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aseprite_resize_canvas

Change the canvas size without scaling artwork. Add room for attack animations or breathing space around a character while anchoring existing pixels.

Instructions

Change the canvas size without scaling the artwork. Use it to add room for an attack animation or breathing space around a character.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
widthYes
anchorNoWhere existing artwork sits in the new canvas (default top-left).
heightYes
documentNoDocument to act on: a short name inside the art folder ("hero"), a relative path, or an absolute .aseprite path. Omit to use the active document.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A3.7/5.0
Behavior3/5

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

With no annotations, the description carries the full burden, and it does disclose the key behavioral trait that artwork is not scaled. However, it omits other important behavior for a canvas mutation: whether reducing width/height discards artwork, and how the anchor interacts with resizing. Useful but incomplete.

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?

Two tight sentences with the core purpose front-loaded and the usage example second. Every sentence earns its place with no filler.

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 a parameterized mutation tool with no annotations, no output schema, and only 50% schema coverage, the description covers purpose and a use case but leaves out resize-specific behavior (shrink effects, anchor default interaction) and any mention of document selection. Adequate but with clear gaps.

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 coverage is 50%: anchor and document are documented, but width/height are bare integers. The description does not compensate by clarifying units, range, or how width/height relate to the anchor. The dimension semantics for width/height are left to the obvious enum/min-max in the schema, so a baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb (Change) and resource (canvas size) and crucially distinguishes the effect from scaling by stating 'without scaling the artwork', implicitly separating it from aseprite_scale_sprite. It does not name any sibling outright, so it stops short of full sibling differentiation.

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?

It gives a concrete when-to-use context ('add room for an attack animation or breathing space around a character'), which is clear and actionable. It offers no exclusions or explicit alternatives (e.g. use crop to trim), so it falls short of the when/when-not bar.

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