Skip to main content
Glama
jdsalasca

Aseprite Asset MCP

by jdsalasca

set_cel_position

Positions a cel on a specified layer and frame by setting its x,y coordinates, with options to create it if missing or copy it from another frame.

Instructions

Set one cel position, optionally creating it from a source cel.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
xYes
yYes
filenameYes
layer_nameYes
frame_indexYes
create_if_missingNo
source_frame_indexNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

C2.7/5.0
Behavior2/5

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

With no annotations, the description carries the full burden of disclosing side effects, but it only says a position is set and a cel may be created from a source cel. It does not state whether existing x/y values are overwritten, what happens for missing layers or frames, what coordinate system is used, or what the source cel contributes. The optional creation behavior is useful, but significant behavioral context is missing.

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 description is a single sentence with no filler, and the primary action is front-loaded. It is appropriately compact, though that compactness comes at the cost of detail that is not supplied anywhere else.

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

Completeness2/5

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

For a mutating tool with seven parameters, no annotations, and no output schema, one sentence is far from complete. Missing information includes when creation is triggered, error behavior for invalid targets, and how this differs from other position-related tools. The description hints at the key optional path but does not make the tool safely invocable by an agent.

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

Parameters2/5

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

Schema description coverage is 0%, so the description must compensate, but it only adds the insight that a source cel may be used when creating the cel, loosely mapping to create_if_missing and source_frame_index. It does not explain x/y semantics, frame_index bounds, or how the source cel's position or pixels are used. This partial compensation is not enough for seven parameters.

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 names a specific action ('Set') and resource ('one cel position'), which distinguishes it from position-related siblings like tween_cel_positions and offset_cel_positions. It also surfaces the optional creation behavior. However, it does not explicitly name any sibling tool or contrast itself with them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool instead of alternatives such as offset_cel_positions, tween_cel_positions, copy_cel, or create_cel. No preconditions are described, such as whether the layer must exist or how create_if_missing relates to source_frame_index. The implied use case is the only signal.

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