SketchUp MCP Server

fillet_edge

Round the edges of a SketchUp group or component by a chosen radius in mm, with adjustable arc segments. Check the returned stats for failed cuts on non-manifold geometry.

Instructions

Round (fillet) edges of a group/component by radius mm with segments arc segments.

By default ALL edges are filleted. Unreliable on non-manifold geometry.

Returns: JSON {id, name, type, bbox_mm|null, edges_filleted, stats{attempted, skipped_no_match, subtract_failed, succeeded}} â€” check stats.subtract_failed == 0 (failed cuts) and stats.skipped_no_match == 0 (edges consumed by earlier cuts).

Input Schema

TableJSON Schema

Name	Required	Description
`id`	Yes	Entity ID from a previous response (integer or its string form)
`radius`	No	Fillet radius in mm
`segments`	No	Arc segments per rounded edge

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

A4.1/5.0

Behavior4/5

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

No annotations are provided, so the description carries full burden. It discloses the destructive/mutating nature (edges are consumed by cuts), the reliability caveat on non-manifold geometry, and the return stats with explicit success criteria. It does not mention permissions or reversibility, but the failure-mode disclosure is strong.

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

Conciseness5/5

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

Four compact sentences: operation, default scope, caveat, return contract. Front-loaded with the core action and every sentence carries information. The escaped quotes are a minor formatting artifact but do not obscure meaning.

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?

An output schema exists, yet the description still summarizes the returned JSON and states how to interpret stats (subtract_failed == 0, skipped_no_match == 0), which is high-value guidance for an agent deciding success. Combined with the mutation caveat, this is complete enough to invoke correctly.

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

Parameters3/5

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

Schema description coverage is 100%, so the schema documents all three parameters, including defaults and units. The description reinforces radius and segments but adds no syntax or format details beyond the schema. Baseline 3 applies.

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?

States a specific verb (Round/fillet) and resource (edges of a group/component) with the key parameters named. The sibling chamfer_edge is a distinct operation, and the description makes the operation unambiguous.

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?

States a default behavior ("By default ALL edges are filleted") and a caveat ("Unreliable on non-manifold geometry"), which gives implied context. However, it does not specify when to use fillet_edge vs chamfer_edge or how to limit the edge selection, leaving the agent to infer.

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