Tune a Levels effect's channel, gamma, clamp, and input/output values to adjust mask contrast and control affected material channels.
Tune a Levels effect, for example to push a mask's contrast.
channel picks what a content Levels affects, such as BaseColor or Roughness.
| Name | Required | Description | Default |
|---|---|---|---|
| uid | Yes | ||
| clamp | No | ||
| gamma | No | ||
| channel | No | ||
| input_max | No | ||
| input_min | No | ||
| output_max | No | ||
| output_min | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v1.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, yet it says nothing about mutation semantics: whether omitted parameters retain their current values, whether changes are undoable, whether this requires an active-editing session, or what happens if the uid has no Levels effect. Only the output schema relieves it of explaining return values.
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?
Two short sentences with the core action front-loaded and no filler. The second sentence is a bit awkwardly phrased ("what a content Levels affects") but is still efficient; the sparseness is a completeness problem, not a verbosity problem.
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?
An eight-parameter, unannotated mutation tool with 0% schema coverage needs substantially more: the description addresses one parameter and never covers the numeric range parameters that define a Levels adjustment. An agent could not confidently construct a call from this plus the bare schema.
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, but it explains only one of eight parameters (channel, with examples BaseColor/Roughness). The seven remaining fields — uid, clamp, gamma, input_min/max, output_min/max — get no meaning, valid ranges, or defaults guidance beyond their names.
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?
"Tune a Levels effect" names a specific verb and resource, and the mask-contrast example makes the effect's role concrete. It does not distinguish this from nearby effect-manipulation siblings such as insert_content_effect, insert_mask_effect, or apply_smart_mask, so an agent must infer that set_levels adjusts an already-existing Levels node.
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 example ("push a mask's contrast") implies a typical usage context, but no explicit when-to-use/when-not-to-use guidance is given, and no alternative tool is named. It also omits the prerequisite that a Levels effect must already exist on the target layer before tuning.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.