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Evidence record · captured 2026-10-10

Anthropic Spreadsheet

A formula-safe spreadsheet workflow covering XLSX, XLSM, CSV, and TSV creation or editing, recalculation, compatibility constraints, source documentation, and financial-model conventions.

Official publisherUnverifiedSource reviewedBehavior not tested
Source review

Editorial assessment

This is a source-only assessment. It does not claim runtime or security testing.

What it does

The skill chooses tools by spreadsheet task, requires formulas rather than hardcoded outputs, forces recalculation and error inspection, and documents compatibility traps for cached values, external links, merged cells, macros, and newer Excel functions.

Best for

  • Creating a professional formula-driven workbook
  • Editing an existing Excel model without destroying conventions
  • Cleaning tabular data into a spreadsheet deliverable

Strengths in the source

  • Explains why openpyxl formula strings need a separate recalculation step.
  • Separates formula evaluation from formula correctness and demands sample checks.
  • Includes disciplined conventions for assumptions, sources, financial inputs, formats, and cross-sheet references.

Limitations

  • The license restricts extraction, copying, derivative work, and distribution outside authorized Anthropic use.
  • LibreOffice does not evaluate every modern Excel function and external links are especially fragile.
  • The skill is file-centric and explicitly excludes Google Sheets API integrations.

When not to use it

  • The primary deliverable is a report, database pipeline, or standalone script
  • Your use would conflict with the pinned Anthropic license terms

Reviewed by Retenta editorial on 2026-10-10; scope: source only.

Files included in this review
  • skills/xlsx/SKILL.md
  • README.md
  • skills/xlsx/LICENSE.txt

Evidence and boundaries

Execution · not tested

Retenta reviewed the pinned source but did not install or execute this skill.

Security · not tested

No sandbox run, dependency audit, or independent security assessment is claimed.

Pinned publisher source
skills/xlsx/SKILL.md
Revision
dbd4588f9e1033efb41dad4bef2f7947c8993d44
License evidence
Anthropic source-available termsThe pinned LICENSE.txt reserves Anthropic's rights and limits use to the applicable Anthropic agreement, with additional restrictions on extraction, copying, derivatives, and distribution.
Last source change
2026-07-16
Independent verification
The source is controlled by Anthropic; Retenta has not independently verified its runtime behavior or security.
Upstream repository
Open publisher repository

Compatibility

Claude Code

documented

Anthropic documents these skills as Claude implementations distributed through its Claude Code plugin marketplace.

Requirements and access

  • openpyxl, pandas, and markitdown as appropriate
  • LibreOffice for formula recalculation
  • Compliance with Anthropic's source-available license terms

Referenced tools

openpyxlpandasmarkitdownLibreOfficerecalc.py

Install from the source

Anthropic documents this skill inside the document skill set; the command installs that set rather than one folder.

View the SKILL.md at its source Verify the publisher's install documentation

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Claude Code plugin install

/plugin marketplace add anthropics/skills
/plugin install document-skills@anthropic-agent-skills

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