Create or update a levels adjustment layer to correct tonal range by setting input/output black and white points, gamma, channel, and opacity.
Create or update a levels adjustment layer.
| Name | Required | Description | Default |
|---|---|---|---|
| gamma | No | 0.1–10. Default 1.0. | |
| channel | No | ||
| layerId | No | ||
| opacity | No | ||
| layerName | No | ||
| inputBlack | No | 0–255. Default 0. | |
| inputWhite | No | 0–255. Default 255. | |
| outputBlack | No | 0–255. Default 0. | |
| outputWhite | No | 0–255. Default 255. |
Changes observed during successful MCP inspections.
v0.5.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It identifies this as a create/update operation but does not disclose permissions, whether updates are destructive, what happens when layerId is omitted, or how existing settings are affected.
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 front-loaded sentence with no redundant or filler text. It is concise and structurally clean, even though brevity contributes to its completeness gaps.
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 9-parameter mutation tool with no annotations and no output schema, the description is far too thin. It does not explain creation versus update semantics, required context, defaults, channel behavior, or return 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 56%, leaving several parameters such as layerId, layerName, opacity, and channel undocumented in the schema. The description adds no parameter meaning at all, so it does not compensate for the gaps.
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 states a specific verb and resource: 'Create or update a levels adjustment layer.' It is clear what the tool does, but it does not explicitly distinguish itself from related siblings such as design_adjust_curves or design_auto_levels.
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?
The description gives no guidance on when to use this tool versus alternatives, nor does it state prerequisites such as whether an existing layer is required. It only restates the create/update action without usage context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.