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Create Parametric Box

create_box_parametric

Build a history-based rectangular box by sketching a rectangle and extruding it, sizing length, width and height with numbers or User Parameter expressions.

Instructions

Create a history-based rectangular box via sketch rectangle + extrude (unlike create_box which uses TemporaryBRepManager). length/width/height accept a number (cm, Fusion internal unit) or a string expression referencing User Parameters (e.g. 'boxL', '56 mm', 'outer - 2 * wall_t'). Call create_parameter first to define named parameters. Unless a parameter says otherwise, lengths and coordinates are in cm (not mm) and angles in degrees.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "length": "<length>",
      "width": "<width>",
      "height": "<height>"
    },
    "name": "create_box_parametric"
  }
}

Input Schema

Name	Required	Description	Default
`plane`	No		xy
`width`	Yes	Along sketch Y: number (cm) or expression
`height`	Yes	Extrude distance: number (cm) or expression
`length`	Yes	Along sketch X: number (cm) or expression
`origin_x`	No
`origin_y`	No
`origin_z`	No	Z-offset of sketch plane (cm)
`body_name`	No	Optional name for the resulting body
`component_name`	No	Target component (omit for root)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 30, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already cover read/write safety hints, and the description adds useful behavioral context: it creates a history feature via sketch+extrude, accepts expressions, and has a create_parameter prerequisite. It does not describe failure modes or return behavior, but with annotations present the added context is meaningful.

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?

The description is dense but front-loaded: purpose and sibling distinction first, then parameter semantics, then the create_parameter prerequisite, then units. Every sentence carries relevant information for correct invocation.

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

Completeness4/5

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

For a 9-parameter creation tool with no output schema, it provides the critical context: method, expression support, prerequisite, and unit convention. It does not explain the plane orientation meaning or what the tool returns, but those gaps are minor given the schema and annotations.

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 67%, so the description must add value. It explains that length/width/height accept either a number in cm or a string expression, gives examples like '56 mm' and 'outer - 2 * wall_t', and clarifies that lengths/coordinates default to cm while angles are degrees. It leaves plane enum semantics and some origin/body/component details to the schema.

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+resource ('Create a history-based rectangular box') and immediately distinguishes it from the sibling create_box by implementation method. An agent can tell which box tool to choose without opening either schema.

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

Usage Guidelines4/5

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

Provides clear context: this is history-based and expression-capable, unlike create_box, and requires create_parameter first for named parameters. It does not explicitly spell out when to prefer create_box, but the alternative and prerequisite are clear enough for routing.

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

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