Apply a solid fill color to a Figma text or frame node using its node ID and RGBA values.
Set the fill color of a node in Figma can be TextNode or FrameNode
| Name | Required | Description | Default |
|---|---|---|---|
| a | No | Alpha component (0-1) | |
| b | Yes | Blue component (0-1) | |
| g | Yes | Green component (0-1) | |
| r | Yes | Red component (0-1) | |
| nodeId | Yes | The ID of the node to modify |
Changes observed during successful MCP inspections.
v0.3.5Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations are absent, so the description carries the full behavioral burden. It adds the supported node types, but does not disclose whether existing fills are replaced, what happens for unsupported node types, or how the optional alpha parameter behaves. 'Set' implies mutation, but deeper behavioral context is missing.
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 short and front-loaded with the action and target, avoiding unnecessary detail. However, the grammar is slightly awkward in the trailing clause, which prevents a higher score.
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 simple setter with fully documented parameters and no output schema, the description is mostly adequate. It is missing edge-case behavior details, especially around the optional alpha parameter and unsupported node types, but remains functional for basic invocation.
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 100%, with clear parameter descriptions, ranges, and required flags. The tool description adds no additional parameter-level meaning, so the baseline 3 is appropriate.
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 concrete action ('Set') and target ('fill color of a node'), and adds supported node types (TextNode or FrameNode). This is clear enough to distinguish it from stroke-related or image-fill siblings, though it does not explicitly name alternatives.
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 when-to-use or when-not-to-use guidance is provided. It does not mention alternatives such as set_stroke_color or set_image_fill, leaving an agent to infer appropriate usage from the tool name and schema alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.