Skip to main content
Glama
dsh18235538266-crypto

onshape-mcp-codex

create_extrude

Creates an extruded 3D feature from a selected sketch, with control over depth, direction, and operation type (new, add, remove, intersect).

Instructions

Create an extrude feature from a sketch

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
nameNoExtrude nameExtrude
depthYesExtrude depth. Bare numbers are mm (CAD default); use "15 mm", "0.5 in", "0.03 m" etc. for explicit units.
endTypeNoEnd condition. BLIND: extrude one direction, `depth` is the length. SYMMETRIC: extrude both sides of the sketch plane, `depth` is the TOTAL length (depth/2 each side). Use SYMMETRIC to avoid building two mirrored BLIND extrudes for features that should straddle their sketch plane.BLIND
elementIdYesPart Studio element ID
documentIdYesDocument ID
workspaceIdYesWorkspace ID
operationTypeNoExtrude operation typeNEW
variableDepthNoOptional variable name for depth
sketchFeatureIdYesID of sketch to extrude
oppositeDirectionNoIf true, extrude in the direction OPPOSITE the sketch normal. For REMOVE on a sketched picked face this tool auto-flips to true regardless of what you pass — because the default (sketch-normal direction) cuts AWAY from the material and silently removes nothing (Onshape returns featureStatus=INFO). Use `forceOppositeDirection: false` to override the auto-flip if you actually need the non-default direction (rare).
forceOppositeDirectionNoEscape hatch that disables the REMOVE+faceId auto-flip. Pass true/false to bypass the heuristic entirely. Only use this for the unusual case of deliberately cutting away from the picked face (e.g. through from underneath). Leaving this absent is correct 99% of the time.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

B3.2/5.0
Behavior2/5

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

No annotations are provided, so the description carries the burden of behavioral disclosure. The one-sentence description does not mention that this mutates the document, requires an existing sketch, can add/remove material, or that REMOVE currently auto-flips direction in certain cases. Those details exist only in the schema, not in the description.

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 a single, front-loaded sentence with no filler or redundancy. Every word earns its place, and the core action and resource are immediately clear.

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

Completeness2/5

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

For a tool with 11 parameters, 5 required inputs, and no output schema, a one-sentence description is not contextually complete. It omits high-level operational context such as the need for an existing sketch, the range of operation types, and what the result or return value looks like. The schema is rich, but the description alone does not orient an agent sufficiently.

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 input schema already documents all 11 parameters, including rich details like depth units, endType behavior, and the oppositeDirection auto-flip. The description itself adds no parameter-level meaning, so the baseline of 3 is appropriate.

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 description uses a specific verb and resource: "Create an extrude feature from a sketch." It clearly identifies the operation and differentiates it from sibling tools like create_revolve or create_thicken by stating the sketch-based source.

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 guidance on when to use this tool versus alternatives. It does not mention prerequisites such as having a sketch already created, nor does it compare against other feature-creation tools like create_revolve or create_thicken.

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