Create Validation

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 24034f36bad7 · 19 Oct 2026Report an issue or request a re-scan

• Publisherghbalf GitHub userOwner of the repository this skill is read from
• Source folderghbalf/freecad-ai/skills/create-validationThe exact folder we audited
• LicenceLGPL-2.1As the repository states it
• Commit pinned for this verdict24034f36bad7A new audit runs when the source changes
• Repository statusNot archivedLast push 2 days ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Generate a draft VALIDATION.md for a skill by analyzing its SKILL.md construction steps

---
name: create-validation
description: Generate a draft VALIDATION.md for a skill by analyzing its SKILL.md construction steps
---

# Create Validation Rules

Generate a draft VALIDATION.md file for a skill by analyzing its SKILL.md.

## WARNING — READ THIS FIRST

**This skill generates a DRAFT, not a finished product.** The generated VALIDATION.md will likely contain errors, especially in volume formulas. You MUST:

1. **Review every check** — does it match what the skill actually builds?
2. **Verify all volume formulas by hand** — volume calculations for complex geometry (shells with posts, lips, ridges) are easy to get wrong. Calculate the expected volume for one set of dimensions and compare with the formula.
3. **Test with `--validate`** — run the skill with known-good parameters and `--validate` to see if the checks pass on correct geometry.
4. **Adjust tolerances** — the defaults (0.5mm for bbox, 5% for volume) may be too tight or too loose for your skill.
5. **Check conditional rules** — if your skill has variants, verify each `when` block covers the right checks.

**Common errors in generated VALIDATION.md:**
- Volume formulas that forget to add/subtract features (posts, holes, lips, ridges)
- Wrong body labels (FreeCAD may rename bodies)
- Missing conditional branches for skill variants
- Tolerances that are too tight for the geometry complexity

## How to use

```
/create-validation skill-name
```

Where `skill-name` is the name of an existing skill (e.g., `enclosure`, `gear`).

## What to do

1. Read the specified skill's SKILL.md using `execute_code`:
   ```python
   import os
   skills_dirs = [
       os.path.expanduser("~/.config/FreeCAD/FreeCADAI/skills"),
   ]
   # Also check built-in skills
   builtin = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "skills") if '__file__' in dir() else ""
   ```
   Or use `get_document_state` context to find the skill path.

2. Analyze the SKILL.md to extract:
   - **Parameters**: from the "Parameters to extract" section. Note types and defaults.
   - **Bodies**: from `create_body` instructions. Note their labels.
   - **Geometry steps**: pad dimensions, pocket depths, post positions, etc.
   - **Variants**: different lid types, optional features, conditional construction steps.

3. Generate VALIDATION.md with this structure:

```markdown
# Validation Rules

## Parameters
(one line per parameter: name: type = default)

## Checks

### Body count
- total_bodies: N

### BodyLabel
- exists: true
- bbox: X_expr, Y_expr, Z_expr (tolerance 0.5)
- volume: formula (tolerance 5%)
- solid_count: 1
- valid_solid: true

#### when variant_param == "value"
- (variant-specific checks)
```

4. Write the file to the skill directory as VALIDATION.md.

5. **IMPORTANT**: After writing, display this message to the user:

> **Draft VALIDATION.md created.** This is a starting point, NOT a finished file.
>
> **You must verify:**
> - All volume formulas — calculate expected values by hand for at least one set of dimensions
> - Body labels match what FreeCAD actually creates (use `get_document_state` after running the skill)
> - Conditional `when` blocks cover all variants
> - Tolerances are appropriate (0.5mm bbox, 5% volume are defaults)
>
> **Test it:** Run `/skill-name args --validate` to check against actual geometry.
>
> **Fix it:** Edit the VALIDATION.md directly if checks fail on correct geometry.

## Rules for generating volume formulas

- **Rectangular shell** (box with hollow interior): `L*W*H - (L-2*T)*(W-2*T)*(H-T)`
  - This gives 4 walls + floor, open top
- **Cylindrical posts** added to interior: `+ N * pi * R**2 * post_height`
  - N = number of posts, R = post radius
- **Cylindrical holes** subtracted: `- N * pi * R**2 * depth`
- **Solid slab** (lid): `L * W * T`
- **Lid with lip**: lip volume + slab volume
- **Use `pi` constant**, not 3.14159 (the expression evaluator supports `pi`)
- **Use `**` for power**, not `^` (the evaluator uses Python's `ast` module)

## Available check types

| Check | Value format | When to use |
|-------|-------------|-------------|
| `exists: true` | — | Always, for each body |
| `bbox: X, Y, Z (tolerance 0.5)` | Expressions, absolute mm | Always, for each body |
| `volume: expr (tolerance 5%)` | Expression, relative % | When geometry has calculable volume |
| `solid_count: N` | Integer | Always (usually 1 per body) |
| `valid_solid: true` | — | Always, for each body |
| `total_bodies: N` | Integer | Once, at document level |
| `has_holes: N` | Integer | When through-all pockets expected |
| `has_feature: "Name"` | String | When specific named features expected |
| `min_children: N` | Integer | When minimum feature count matters |

## Parameter type reference

| Type | Default syntax | Example |
|------|---------------|---------|
| `float` | `= 2.5` | `T: float = 2` |
| `int` | `= 4` | `count: int = 4` |
| `str` | `= value` | `lid_type: str = screw` |
| `bool` | `= false` | `add_vents: bool = false` |

Excerpt, first 4,993 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/ghbalf/freecad-ai
git -C freecad-ai checkout 24034f36bad7

Works in

1. 2026-10-19
   ✓SAFE B 89 / 100

   first audit · source 24034f36bad7

Questions about Create Validation

• github.com/ghbalf/freecad-ai/tree/master/skills/create-validatio — the audited source at commit 24034f36bad7 and every finding aboveObserved · 19 Oct 2026

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