excel-sheet

excel-sheet is a skill for Codex from PracticalSwan/agent-skills. It costs 40 tokens per session (1,096 once invoked), scanned A, original, MIT.

A skill for working with Microsoft Excel workbooks, the spreadsheet files usually ending in .xlsx. It covers creating and editing workbook structure, formulas, formatting, charts, pivot tables, and data analysis.

In plain words
What is it for?
Creating or updating workbooks, converting CSV data, adding formulas and formatting, and building charts or pivot tables.
Why use it?
It helps turn spreadsheet requirements into usable Excel files while preserving important layout and calculations.

Skill for Codex

Written for Codex: reads ~/.codex or $CODEX_HOME. Also seen: mentions subagents; mentions Claude Code; mentions Codex.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/practicalswan/agent-skills/excel-sheet
Any agent
npx skills add PracticalSwan/agent-skills --skill excel-sheet
Clone the repo
git clone --depth 1 https://github.com/PracticalSwan/agent-skills

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for excel-sheet

README.md
[![agentmods](https://agentmods.dev/badge/skills/practicalswan/agent-skills/excel-sheet.svg)](https://agentmods.dev/skills/practicalswan/agent-skills/excel-sheet)
Your own site
<a href="https://agentmods.dev/skills/practicalswan/agent-skills/excel-sheet"><img src="https://agentmods.dev/badge/skills/practicalswan/agent-skills/excel-sheet.svg" alt="Measured on agentmods" height="20"></a>
Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,096 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00040 $0.01096
Opus 5 $0.00020 $0.00548
Sonnet 5 $0.00008 $0.00219
Haiku 4.5 $0.00004 $0.00110

Measured 2d ago against content hash fd0ee0bbf91c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

excel-sheet scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/csv-to-xlsx.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

excel-sheet/SKILL.md · 107 lines

How it starts

The opening of the file, as written. The whole thing — 107 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Excel Spreadsheet Workflows

Tech Stack Target / Version: Excel desktop or openpyxl-based spreadsheet automation with current OOXML-compatible workflows.

Use this skill when the deliverable is an .xlsx workbook or when spreadsheet structure matters.

  • Leverage native parallel subagent dispatch and 200k+ context windows where available.

Current MCP Reality

Excel MCP tooling is host-dependent. In GitHub Copilot, Excel actions may appear as grouped Office tools. In Codex or Claude, those tools may be absent entirely. Treat the included Python script as the reliable fallback.

Activation Conditions

Use symptom -> action triggers: when one matches, apply this skill and verify with the protocol below.

  • Creating or updating workbooks
  • Converting CSV data into structured Excel output
  • Applying formulas, formatting, charts, or pivots
  • Producing spreadsheet deliverables when layout matters

Practical Workflow

  1. Confirm whether the client exposes spreadsheet MCP tools.
  2. If yes, inspect the actual tool names before assuming a wrapper exists.
  3. If no, use the local converter or author the workbook with openpyxl.
  4. Validate formulas and chart ranges before claiming the workbook is ready.

MCP Fallback – Native Automation

When MCP is unavailable, use native automation: openpyxl for .xlsx, CSV export for flat data, and manual formula inspection for high-risk calculations. Preserve formulas, number formats, sheet names, hidden sheets, and workbook metadata, then reopen or parse the workbook before claiming success.

Anti-Patterns

  • Treating source content as already clean: Formatting automation will happily preserve broken or inconsistent input.
  • Skipping an open-file verification pass: Documents and spreadsheets often fail in the destination app, not in the script output.
  • Automating irreversible edits without checkpoints: A small mapping mistake can affect an entire workbook or document.

Verification Protocol

Before claiming "skill applied successfully":

Read the full file on GitHub · 107 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago Changed fd0ee0bbf91c
  2. 5d ago First seen · 107 lines · 40 tokens per session scan A e86ad290917e

Subscribe to this mod's changes

excel-sheet is a skill published in the GitHub repository PracticalSwan/agent-skills (13 stars, last pushed 5d ago), licensed MIT. It adds 40 tokens to every session and 1,096 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.