Xlsx
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
Why this rating
Deterministic checks triggered by the tool capabilities and evidence.
- Locality: Local
SKILL.md uses local Python/LibreOffice tooling over local spreadsheet files.
- Data access: Sensitive
Workbooks may contain financial models, assumptions, and business-sensitive tabular data.
- Action surface: Write
Supports creating/modifying sheets, formulas, and file outputs with recalculation.
Best practices
Follow these steps to reduce risk when using this skill.
- Keep source and output spreadsheets in access-controlled directories.
- Validate formulas and recalculation results before sharing generated workbooks.
- Preserve backups of original templates before structural edits or bulk updates.
Evidence links
Public sources backing the indicator assignments.
Always be careful when navigating away from the website.
Max-risk rule
If any capability reaches a higher level, the entire indicator level bumps up to keep ratings deterministic and easy to scan.