Create, edit, analyze, or convert Excel spreadsheets (.xlsx, .xlsm) where the workbook file is the primary deliverable.
SkillScore74Maintained
Automatic
◆Finance & Accounting pack
Last verified 8/28/2026
What it changes
Passed 15 of 20 test cases with the skill, and 12 of 20 without it.
Without skill61%
With skill74%
Checks it passed that the model alone missed
Background pattern fill color is set to yellow (RGB 255, 255, 0).
Font color for external workbook links is set to red (RGB 255, 0, 0).
Year values are formatted as text strings rather than numeric integers.
and 1 more in the full report
4 fixed13 passed either way5 still failing1 broke
Pass-rate lift
+13 pp
Tokens
+107%
Agent turns
0%
Response time
-35%
Model gemini-3.6-flashMeasured 8/28/2026v117 of 23 cases passed with skill · 20 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 4 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 4
Prompt
We have a financial consolidation workbook that pulls historical baseline figures directly from a separate external file on the network (`[2023_Audited_Baseline.xlsx]Sheet1!$B$10`). How should this external link reference be visually styled in openpyxl?
What was checked, without and with the skill
Checked
Without skill
With skill
Font color for external workbook links is set to red (RGB 255, 0, 0).
Missed
Passed
case-05 · gemini-3.6-flash · 8/28/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md319 lines2 filesincludes scripts
Requirements for Outputs
All Excel files
Professional Font
Use a consistent, professional font (e.g., Arial, Times New Roman) for all deliverables unless otherwise instructed by the user
Zero Formula Errors
Every Excel model MUST be delivered with ZERO formula errors (#REF!, #DIV/0!, #VALUE!, #N/A, #NAME?)
Comprehensive spreadsheet creation, editing, and analysis with support for formulas, formatting, data analysis, and visualization. When Claude needs to work with spreadsheets (.xlsx, .xlsm, .csv, .tsv, etc) for: (1) Creating new spreadsheets with formulas and formatting, (2) Reading or analyzing data, (3) Modify existing spreadsheets while preserving formulas, (4) Data analysis and visualization in spreadsheets, or (5) Recalculating formulas
Passive income portfolio analysis — activate when user asks about dividend yields, Treasury rates, REIT income, monthly passive income goals, or portfolio yield optimization. Scans 4 asset classes, ranks by risk-adjusted return, and builds allocations targeting a specific monthly income.