Adjusts hue, saturation, and lightness on an opaque cel while keeping alpha intact. Use to fine-tune colors without affecting transparency.
Shift hue, saturation, and lightness on an opaque cel while preserving alpha.
| Name | Required | Description | Default |
|---|---|---|---|
| filename | Yes | ||
| hue_shift | No | ||
| layer_name | Yes | ||
| frame_index | Yes | ||
| lightness_shift | No | ||
| saturation_shift | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden; it does add useful context by constraining the operation to an opaque cel and stating that alpha is preserved. However, it omits whether the edit is in-place, reversible, what happens to semi-transparent pixels, and what the tool returns.
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?
One sentence, front-loaded with the action, and no filler. Every clause adds relevant information: target, operation, scope, and preserved channel.
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 six-parameter mutation tool with no output schema and no annotations, the description is adequate but thin. The core operation is clear enough to invoke, but an agent is left without return-behavior or failure-mode expectations.
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%, so the description must compensate. It conveys the conceptual mapping from hue/saturation/lightness to the three shift parameters, but it does not explain the identifier parameters (filename, layer_name, frame_index) or the bounds/clamping behavior beyond what the schema already shows.
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 ('Shift') with a concrete resource ('opaque cel') and names the affected properties (hue, saturation, lightness), plus the alpha-preservation constraint. This clearly distinguishes it from nearby color tools like adjust_brightness_contrast and invert_colors.
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 is given for when to use this tool instead of related tools such as adjust_hsl_native, adjust_brightness_contrast, replace_color, or apply_color_grade. The 'opaque cel' phrase is the only implicit scoping, with no exclusions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.