Set a named layer's opacity from 0 to 255 in an Aseprite file. Provide the filename, layer name, and opacity value to update the layer's transparency.
Set a named layer opacity from 0 to 255.
| Name | Required | Description | Default |
|---|---|---|---|
| opacity | Yes | ||
| filename | Yes | ||
| layer_name | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It only restates the opacity range already present in the schema and does not mention side effects, persistence, error behavior, or what happens when the layer does not exist.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, compact sentence with no filler. The core action, target, and constraint are all front-loaded, making it easy to read and parse.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is simple and all required parameters are covered by the schema, so this is minimally viable. However, with no annotations, no output schema, and no behavioral context, the description leaves gaps around expected side effects and failure modes.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, but the description adds little beyond the schema: it repeats the opacity range and leaves filename and layer_name to be inferred from their names. The description does not compensate for the missing parameter documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb and resource: 'Set a named layer opacity', and it states the valid range (0 to 255). It is clearly distinguishable from sibling tools like set_layer_visibility, set_layer_blend_mode, and set_cel_opacity because it names 'layer' and 'opacity' explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
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 versus alternatives such as set_cel_opacity or set_layer_visibility. No when/when-not scenarios, prerequisites, or exclusions are provided, leaving the agent to infer the appropriate context from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.