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partdesign_draft

Applies an undoable draft angle to selected solid faces, optionally using a neutral plane or pull direction, to taper model geometry in FreeCAD.

Instructions

Taper selected solid faces by a draft angle (PartDesign::Draft) (undoable).

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": {
      "object_name": "<object_name>",
      "faces": "<faces>"
    },
    "name": "partdesign_draft"
  }
}

Input Schema

Name	Required	Description	Default
`name`	No
`angle`	No
`faces`	Yes
`doc_name`	No
`reversed`	No
`object_name`	Yes
`neutral_plane`	No
`pull_direction`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Nov 14, 2026

TDQS

C2.9/5.0

Behavior3/5

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

The description adds '(undoable)', which is real behavioral context beyond the annotations, and is consistent with readOnlyHint=false. However, for a mutation tool with eight inputs it says nothing about required selection state, whether the operation fails on non-planar faces, or what happens to adjacent geometry.

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?

One short, front-loaded sentence with no filler; the verb and resource come first. It is efficient, though the brevity is partly under-specification rather than deliberate concision.

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?

With eight parameters, two required, zero schema descriptions, and output schema present, the description is too thin for the tool's complexity. Return values need not be described, but the draft-direction parameters are essential to calling this correctly and are never addressed.

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

Parameters2/5

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

Schema description coverage is 0%, so the description must compensate and largely fails: it only implies the meaning of `faces` and `angle`. The geometrically critical parameters `neutral_plane`, `pull_direction`, and `reversed` — which determine the draft axis and hinge — are entirely unexplained.

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 ('taper'), a specific resource ('selected solid faces'), and the operative parameter ('draft angle'), plus the FreeCAD feature type (PartDesign::Draft). It is not tautological, though it does nothing to distinguish this from adjacent feature tools like partdesign_thickness.

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 a draft versus thickness, loft, or a chamfer, and no prerequisites (must a body exist? must faces be planar?). The agent must infer applicability from the name alone.

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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