How do I install the XLSX skill?

Run npx skillmds@latest add itsual/xlsx in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with XLSX?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

itsual (@itsual) published this skill. Their other Agent Skills are listed on their SkillMD profile.

XLSX by itsual — Agent Skill

Name: XLSX
Author: itsual

XLSX

Create well-structured, usable Excel spreadsheets (.xlsx) with clear data layout, formulas, formatting, and analysis-ready tables. Use when the user asks for a spreadsheet, Excel file, tracker, model, dashboard data, or .xlsx. Prefer clean data tables over purely visual formatting.

itsual Updated Sep 21, 2026

File contents

XLSX – Spreadsheet Production

Overview

Produce spreadsheets that are easy to understand, maintain, and analyze. Separate raw data from presentation, use formulas correctly, and make the structure obvious to the next person (or agent) who opens the file.

When to Use

User requests an Excel file, spreadsheet, tracker, financial model, data table, or .xlsx
Data needs calculation, filtering, or structured analysis
Deliverable must be usable in Excel / Google Sheets / LibreOffice Calc

Core Principles

One clear purpose per sheet when possible
Put raw data in clean tabular form (no merged cells in data regions)
Use formulas instead of hard-coded calculated values
Separate inputs, calculations, and outputs
Apply number formats, headers, and freeze panes thoughtfully
Make assumptions and units visible
Avoid unnecessary colors and decorations that hinder analysis

Recommended Practices

Header row with clear column names
Consistent data types per column
Use tables (ListObjects) where helpful
Named ranges for key inputs
Clear separation of inputs (often highlighted) vs. results
Include a short “Notes” or “Assumptions” area when the model is non-trivial

Verification

Formulas calculate correctly and are not overwritten with values
Data is in a clean, filterable/tabular layout
Units, currency, and percentages are formatted properly
Key assumptions are visible
File opens without errors in major spreadsheet applications
File is saved as .xlsx

Common Pitfalls

Merged cells in the middle of data ranges
Hard-coded values that should be formulas
Hidden logic that is difficult to audit
Over-formatting that makes the sheet fragile

---name: xlsxdescription: Create well-structured, usable Excel spreadsheets (.xlsx) with clear data layout, formulas, formatting, and analysis-ready tables. Use when the user asks for a spreadsheet, Excel file, tracker, model, dashboard data, or .xlsx. Prefer clean data tables over purely visual formatting.---# XLSX – Spreadsheet Production## OverviewProduce spreadsheets that are easy to understand, maintain, and analyze. Separate raw data from presentation, use formulas correctly, and make the structure obvious to the next person (or agent) who opens the file.## When to Use- User requests an Excel file, spreadsheet, tracker, financial model, data table, or .xlsx- Data needs calculation, filtering, or structured analysis- Deliverable must be usable in Excel / Google Sheets / LibreOffice Calc## Core Principles- One clear purpose per sheet when possible- Put raw data in clean tabular form (no merged cells in data regions)- Use formulas instead of hard-coded calculated values- Separate inputs, calculations, and outputs- Apply number formats, headers, and freeze panes thoughtfully- Make assumptions and units visible- Avoid unnecessary colors and decorations that hinder analysis## Recommended Practices- Header row with clear column names- Consistent data types per column- Use tables (ListObjects) where helpful- Named ranges for key inputs- Clear separation of inputs (often highlighted) vs. results- Include a short “Notes” or “Assumptions” area when the model is non-trivial## Verification- [ ] Formulas calculate correctly and are not overwritten with values- [ ] Data is in a clean, filterable/tabular layout- [ ] Units, currency, and percentages are formatted properly- [ ] Key assumptions are visible- [ ] File opens without errors in major spreadsheet applications- [ ] File is saved as .xlsx## Common Pitfalls- Merged cells in the middle of data ranges- Hard-coded values that should be formulas- Hidden logic that is difficult to audit- Over-formatting that makes the sheet fragile

Frequently asked questions