SketchUp MCP Server

create_circle

Creates a true circular curve in SketchUp from a center point and radius, with optional plane normal and segment count, returning circle geometry and bounding box.

Instructions

Create a true circular curve in SketchUp.

All linear values are millimeters.

center is the circle center [x, y, z]. radius is the true circle radius in mm. normal defines the plane perpendicular to the circle. segments controls geometric resolution; higher values produce a more accurate circular approximation.

Returns JSON containing: {id, name, type, center_mm, radius_mm, normal, segments, bbox_mm{min,max}}.

Input Schema

TableJSON Schema

Name	Required	Description
`name`	No	Optional name for the circle group
`center`	Yes	Circle center [x, y, z] in mm
`normal`	No	Circle plane normal vector [x, y, z]
`radius`	Yes	Circle radius in mm
`segments`	No	Number of segments used to represent the circle

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

B3.3/5.0

Behavior3/5

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

With no annotations, the description carries the full burden. It usefully discloses units (mm) and the exact JSON return shape including bbox, but is silent on side effects such as whether a named group is created, whether the operation is undoable, or any permission/state requirements.

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?

Well front-loaded: purpose first, then unit convention, then per-parameter notes, then return shape. Slight redundancy in restating parameter names already titled in the schema, but little waste overall.

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

Completeness3/5

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

An output schema exists, so spelling out the return type is bonus rather than necessary. For a geometry-mutating tool with no annotations, the description leaves side effects (grouping, undo, model state) and the create_circle vs create_curve distinction unaddressed.

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 baseline is 3. The description adds genuine meaning by explaining that normal defines the perpendicular plane and that higher segments yield a more accurate approximation, clarifying the effect of parameters beyond their bare schema text.

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

Purpose4/5

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

The description gives a specific verb+resource ('Create a true circular curve in SketchUp') and pins down scope with units and return shape. It does not, however, differentiate itself from the sibling create_curve, which an agent would plausibly reach for instead.

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

Usage Guidelines2/5

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

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as create_curve or create_component. The agent must infer when a circle is appropriate versus a generic curve.

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