SketchUp MCP Server

set_material

Assign a material or color to a SketchUp group or component using named colors or hex codes. Painting affects only the specified instance.

Instructions

Assign a material (color) to a group or component.

material accepts a named color â€” red, green, blue, yellow, cyan, turquoise, magenta, purple, white, black, brown, wood, orange, gray, grey â€” or a 6-digit hex string like "#a05030" (#rrggbb). Anything else fails with error -32602. Named colors are case-insensitive. Painting affects only this instance (it is made unique first). That applies to groups/components; painting a raw face/edge id (obtainable via get_selection) colors the shared definition â€” all instances show it.

Returns: JSON {id, name, type, bbox_mm{min,max}|null}.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`id`	Yes	Entity ID from a previous response (integer or its string form)
`material`	Yes	Named color or 6-digit hex string like #a05030

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.1Sep 11, 2026

TDQS

A4.4/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full behavioral burden and does so thoroughly: it lists accepted material formats, case-insensitivity, error code -32602 for invalid input, the side effect of making an instance unique before painting, and the distinction that painting raw face/edge ids affects shared definitions. It also describes the return shape, though an output schema exists.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose, followed by important behavioral details in a logical order. Sentences are information-dense and mostly earn their place, though the final 'Returns' line is slightly redundant given the output schema. Overall, it is efficient and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a two-parameter mutation tool with no annotations and an existing output schema, the description provides a complete picture: accepted inputs, error handling, side effects, special-case behavior for raw ids, and return shape. Nothing critical for correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already documents both parameters. The description exceeds the baseline by enumerating all accepted named colors, specifying the hex format (#rrggbb), noting case-insensitivity, and explaining the error behavior for invalid materials. It adds meaningful context beyond the schema's brief parameter descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The first sentence states a specific verb (Assign) and resource (material/color) to a group or component. It immediately distinguishes the tool's function from all siblings, none of which set materials. The description leaves no ambiguity about what the tool does.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the clear purpose statement, and the description provides context about different behaviors for groups/components versus raw face/edge ids. However, it does not explicitly state when to use this tool versus alternatives, nor does it list any prerequisites or exclusions. The guidance is present but not direct.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.