Xlsx Toolkit

# Create a "Xlsx Toolkit" AI Skill

I want you to help me set up a reusable AI skill that I can use in future conversations. Read the complete skill definition below, then help me install it.

## Complete Skill Definition

# Xlsx Toolkit

Audit `.xlsx` files using the standard library only — no `openpyxl` required. Reads OOXML directly via `zipfile` + `xml.etree`.

---

## Table of Contents

- [Keywords](#keywords)
- [Quick Start](#quick-start)
- [Core Workflows](#core-workflows)
- [Tools](#tools)
- [Reference Guides](#reference-guides)
- [Templates](#templates)
- [Best Practices](#best-practices)

---

## Keywords

xlsx, Excel, spreadsheet, workbook, financial model, formula audit, hidden sheets, external references, named ranges, data validation

---

## Quick Start

```bash
python scripts/xlsx_auditor.py model.xlsx
```

Outputs: sheet count and names, hidden-sheet count, cell count per sheet, formula count per sheet, external link count, named range count, data validation rule count.

---

## Core Workflows

### Workflow 1: Pre-Send Workbook Audit

**Goal:** Catch the issues that embarrass the sender — leftover hidden sheets, broken external links, unused named ranges, formulas referencing local file paths.

**Steps:**
1. Run audit
2. Hidden sheets > 0 → confirm intentional or delete
3. External links > 0 → verify links point to public / shared sources, not your local drive
4. Named-range count anomalies (very high) → likely cruft from prior model versions; clean up
5. Re-run until clean

**Time Estimate:** 5-10 minutes per workbook.

### Workflow 2: Financial Model Review

**Goal:** Quantify the rough complexity of a financial model before reading cell-by-cell.

**Steps:**
1. Run audit; capture per-sheet cell counts and formula counts
2. Sheets with formula density > 70% are calculation sheets; should be well-structured
3. Sheets with formula density 0-10% are inputs; should be obviously labeled
4. Sheets with formula density 10-70% are mixed — easiest place for errors to hide
5. Cross-reference with `references/financial_model_audit_guide.md`

**Time Estimate:** 30-60 minutes per model audit (audit + targeted reading).

### Workflow 3: Workbook Handoff Check

**Goal:** Ensure a workbook handed off to another team or partner won't break on their machine.

**Steps:**
1. Run audit
2. External links → re-link to shared paths (OneDrive, SharePoint, S3) or hard-code values
3. Custom named ranges → document if recipient is expected to extend; remove if internal
4. Macros (xlsm) → audit shows non-`.xlsx` extension expected; convert if recipient cannot run macros
5. File size > 10 MB → consider splitting or removing image / chart blobs

**Time Estimate:** 10-20 minutes per workbook.

---

## Tools

### xlsx_auditor.py

Reads a `.xlsx` file as a ZIP archive and parses OOXML directly.

```bash
python scripts/xlsx_auditor.py model.xlsx
python scripts/xlsx_auditor.py model.xlsx --json
```

**Reports:**
- Sheet list with name, hidden status, cell count, formula count, formula density %
- Total cell and formula counts
- Named ranges and their scopes
- External link references (file paths or URLs)
- Data validation rule count
- File size

**Limits:**
- Does **not** evaluate formulas. To check whether formulas are *correct*, use Excel itself or a financial-model-checker library.
- Does **not** read cell values for non-shared-string cells beyond counting; full value extraction requires more parsing than this tool does.

---

## Reference Guides

- **`references/financial_model_audit_guide.md`** — Patterns for auditing financial models; common error categories; defensive structure tips

---

## Templates

- **`assets/workbook_handoff_checklist.md`** — Pre-send xlsx sign-off checklist

---

## Best Practices

- **Hide internal-only sheets only when intended.** If a sheet is hidden because it's WIP, delete it before sending.
- **Avoid external links across handoffs.** A formula referencing `'C:\Users\you\Desktop\old-model.xlsx'` is the workbook equivalent of leaving your laptop name in the document author field.
- **Name your inputs.** Cells like `Inputs!B7` mean nothing. Named ranges like `WACC` and `RevenueGrowth` survive structural changes.
- **One model, one purpose.** Workbooks that calculate, present, and serve as a database of records always end up broken.

---

## Integration Points

- Pairs with `finance/` skills for financial-model review
- Pairs with `c-level-advisor/cfo-advisor` for board-pack workbook review
- Used by `data-analytics/` for ad-hoc analytics handoff

---

## What I Need You to Do

First, detect which platform I'm using (Claude.ai, ChatGPT, etc.) and follow the matching instructions below.

### If I'm on Claude.ai:

Walk me through these exact steps:

1. **Create the Project:** Tell me to go to **claude.ai > Projects > Create project** and name it **"Xlsx Toolkit"**

2. **Add Project Knowledge:** Give me the COMPLETE skill definition above as a single copyable text block inside a code fence. Tell me to click **"Add content" > "Add text content"** inside the project, then paste that entire block. Do NOT say "paste from above" -- give me the actual text to copy right there.

3. **Set Custom Instructions:** Tell me to open project settings and paste this exact instruction:
   "You are an expert Xlsx Toolkit in the Documents domain. Use the project knowledge as your expertise. Follow the workflows, frameworks, and templates defined there. Always provide specific, actionable output."

4. **Test It:** Give me a specific sample prompt I can use inside the new project to verify it works. Pick a real task from the skill's workflows.

### If I'm on ChatGPT:

Walk me through these exact steps:

1. **Create a Custom GPT:** Tell me to go to **chatgpt.com > Explore GPTs > Create**
2. **Configure it:**
   - Name: **"Xlsx Toolkit"**
   - Description: "Audit Microsoft Excel (.xlsx) workbooks for sheet count, cell count, formula density, external references, named ranges, hidden sheets, and data validation rules. Use when reviewing a financial model, sharing a workbook externally, or when the user mentions xlsx audit, spreadsheet review, formula audit, or workbook leakage check."
   - Instructions: Give me the COMPLETE skill definition above as a single copyable text block inside a code fence to paste into the Instructions field. Do NOT say "paste from above."
3. **Test It:** Give me a sample prompt to verify it works.

### If I'm on another platform:
Ask which tool I'm using and adapt the instructions accordingly.

## Important
- Always provide the full skill text in a ready-to-copy code block -- never tell me to "scroll up" or "copy from above"
- Keep the setup steps simple and numbered
- After setup, test it with me using a real workflow from the skill

Source: https://github.com/borghei/Claude-Skills/tree/main/documents/xlsx-toolkit/SKILL.md