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tbrito88
by tbrito88

Create Cylinder

create_cylinder

Create a cylinder or cone primitive in Fusion 360 by defining radius, height, base center, and axis or direction vector for angled or inclined geometry.

Instructions

Create a cylinder (or cone, with top_radius) primitive (non-parametric via TemporaryBRepManager). The base circle is centred at (base_x, base_y, base_z); the body extends height along axis, or along (direction_x, direction_y, direction_z) when given — any direction, e.g. an inclined valve bore. Unless a parameter says otherwise, lengths and coordinates are in cm (not mm) and angles in degrees.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
axisNoCylinder axis directionz
base_xNo
base_yNo
base_zNo
heightYes
radiusYes
top_radiusNoRadius at the far end (cone); default = radius
direction_xNoAxis direction vector (overrides axis)
direction_yNo
direction_zNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A3.8/5.0
Behavior4/5

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

Annotations cover safety (readOnly=false, idempotent=false, destructive=false), so the bar is lower. The description adds valuable behavioral context beyond that: the result is a non-parametric body, the base circle position convention, that direction_* overrides axis, and the critical units caveat (cm not mm, degrees). It stops short of saying whether the new body is selected/merged or what happens on failure.

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?

A tight paragraph where each clause adds information (variant, mechanism, geometry layout, axis override, units). The nested parenthetical about TemporaryBRepManager slightly interrupts flow, but nothing is redundant.

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 10-parameter primitive-creation tool with no output schema, the description supplies the geometry semantics, the non-parametric nature, and the non-obvious cm/degree unit convention. It is largely self-sufficient; only the return value and any preconditions (an open design/component context) are left implicit.

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 description coverage is only 30%, so the description must compensate, and it largely does: it explains base_x/y/z as the base circle centre, that height runs along axis, that direction_x/y/z override axis, that top_radius produces a cone, and the global unit convention for lengths and angles. The few remaining undescribed params (e.g., direction_y/z) are inferable from the direction_x note.

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?

States a specific verb and resource ('Create a cylinder... primitive') and even names the cone variant via top_radius, plus the underlying mechanism (TemporaryBRepManager, non-parametric). However, it does not differentiate itself from sibling primitive creators like create_box, create_sphere, or create_torus, nor from parametric feature tools such as extrude.

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?

The 'non-parametric via TemporaryBRepManager' note implicitly signals when this is appropriate (throwaway geometry vs. a parametric feature), and the direction-vector example ('an inclined valve bore') hints at use cases. But there is no explicit when-to-use/when-not guidance or named alternative among the many sibling creation tools.

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