Set brightness and contrast values for a specific layer of an Aseprite sprite, with additive ranges from -255 to 255 for targeted image tone corrections.
Adjust brightness (-255..255, additive) and contrast (-255..255) of a layer.
| Name | Required | Description | Default |
|---|---|---|---|
| frame | No | Default: 1. | |
| layer | No | ||
| contrast | No | Default: 0. | |
| filename | Yes | ||
| brightness | No | Default: 0. |
Changes observed during successful MCP inspections.
v0.10.0Input schema / properties / brightness / descriptionAdded value: +"Default: 0."Input schema / properties / brightness / titleRemoved value: -"Brightness"Input schema / properties / contrast / descriptionAdded value: +"Default: 0."Input schema / properties / contrast / titleRemoved value: -"Contrast"Input schema / properties / filename / titleRemoved value: -"Filename"Input schema / properties / frame / descriptionAdded value: +"Default: 1."Input schema / properties / frame / titleRemoved value: -"Frame"Input schema / properties / layer / anyOfRemoved value: -[
- {
- "type": "string"
- },
- {
- "type": "null"
- }
-]Input schema / properties / layer / defaultRemoved value: -nullInput schema / properties / layer / titleRemoved value: -"Layer"Input schema / properties / layer / typeAdded value: +"string"Input schema / titleRemoved value: -"adjust_brightness_contrastArguments"v0.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false and openWorldHint=false, so the mutating, local nature is known. The description adds one genuinely useful behavioral trait - brightness is 'additive' - but says nothing about reversibility, whether changes are baked into pixels, or permission requirements.
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?
A single front-loaded sentence that names the operation, both adjustable dimensions, the valid range, the compositing mode, and the target scope. No filler.
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?
For a 5-parameter mutating tool with no output schema and only 60% schema coverage, the description covers the two numeric parameters well but leaves frame/layer/filename and the mutation's side effects unspecified. Adequate but with clear gaps.
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 coverage is 60% and the schema only documents defaults, so the description's ranges (-255..255) and the additive semantics for brightness do add meaning. However, frame, layer, and filename receive no semantic explanation in either place, leaving a partial gap.
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?
States a specific verb ('Adjust') plus the exact resources (brightness and contrast) and the scope ('of a layer'), with valid ranges in parentheses. It does not differentiate itself from the sibling adjust_hue_saturation, but the operation itself is unmistakable.
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?
No guidance on when to use this versus the other adjustment tools (adjust_hue_saturation, desaturate, gradient_map) or when not to. The agent must infer applicability from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.