--- title: "Anthropic Spreadsheets: review, setup & limitations · Undominated.ai" canonical: https://undominated.ai/skills/anthropics-xlsx/ description: "Keeps spreadsheet formulas editable and requires recalculation plus explicit inspection of formula-error results." --- # Anthropic Spreadsheets: review, setup & limitations · Undominated.ai > Keeps spreadsheet formulas editable and requires recalculation plus explicit inspection of formula-error results. [← Explore all skills](/skills/) DOCUMENTS / Anthropic # Anthropic Spreadsheets Keeps spreadsheet formulas editable and requires recalculation plus explicit inspection of formula-error results. See setup guidance ↓Original source ↗ SOURCE REVIEW Reviewed 2026-09-21 Evidence 5 linked sources Publisher Anthropic Licence Anthropic custom terms ↗ Revision 34040c9c5685 Read what was—and wasn’t—checked ↓ “Use this skill any time a spreadsheet file is the primary input or output. This means any task where the user wants to: open, read,” Anthropic · upstream description ↗ Our analysis follows below. 01 / THE REASONING ## Why this made the selection. - Distinguishes formula expressions from cached calculated values, a common source of misleading workbook output. - The inspected recalculation helper checks for vulnerable external-workbook links before rewriting the file. ### A good fit for - Producing a formula-driven workbook - Repairing or restructuring a spreadsheet while preserving its conventions ### Weigh up before choosing - Recalculation uses LibreOffice and the guide excludes several newer Excel functions that this environment cannot evaluate. - An errors_found result can still exit successfully; parse the JSON status rather than relying on exit code alone. - Recalculation rewrites the workbook; --force can accept destructive external-link loss. Restricted Anthropic terms apply. 02 / THE REVIEW RECORD ## What we actually inspected. Source review has boundaries. A clear record is more useful than a “safe” badge. ### Material inspected - skills/xlsx/SKILL.md - skills/xlsx/scripts/recalc.py - skills/xlsx/LICENSE.txt ### Our findings - The helper creates an isolated LibreOffice profile, recalculates, saves, then reads cached cells for error values. - It refuses a detected external-link risk unless forced and warns that its detection is not exhaustive. - The instructions warn that saving a data_only workbook can replace formulas with values and that macro preservation needs explicit handling. ### Not established by this review - Source inspection only; no skill installation or workflow execution was performed. The review applies to the material and revision named here. A newer upstream release can change its behavior. 03 / PUT IT TO WORK ## Add a skill to your workflow. Upstream setup instructions ↗ DOCUMENTED COMMAND /plugin install document-skills@anthropic-agent-skills Copy command ↗ Copying does not execute this command. It may retrieve a newer version than the reviewed source. - In Claude Code, first register the official marketplace with /plugin marketplace add anthropics/skills. - Install the document-skills plugin under the applicable Anthropic agreement, or use the document capabilities supplied in Claude. - This catalogue does not redistribute these restricted definitions or offer a cross-agent copying command. ### Before you start - Claude Code or an eligible Claude service - Applicable Anthropic service access and terms - A writable source copy and the complete spreadsheet helper package ### Compatibility Claude document-skills plugin · Python openpyxl/pandas and LibreOffice ### Read and rewrite local workbooks - Read and rewrite local workbooks - Launch LibreOffice with a generated recalculation macro - Optional destructive override for external links ### Cost model Access follows the Anthropic service agreement; recalculation uses local compute. 04 / FOLLOW THE EVIDENCE ## The source trail. Our notes are separate from the original resource. Check upstream before adopting a new version. - Skill definition at reviewed revision ↗ Checked 2026-09-21 https://github.com/anthropics/skills/blob/34040c9c568585f6929bedeaad110ad08f079624/skills/xlsx/SKILL.md Supports: summary, upstreamDescription, whySelected, bestFor, limitations, review, compatibility, access - Reviewed reference or helper: scripts/recalc.py ↗ Checked 2026-09-21 https://github.com/anthropics/skills/blob/34040c9c568585f6929bedeaad110ad08f079624/skills/xlsx/scripts/recalc.py Supports: review, limitations, access - Upstream license or licensing declaration ↗ Checked 2026-09-21 https://github.com/anthropics/skills/blob/34040c9c568585f6929bedeaad110ad08f079624/skills/xlsx/LICENSE.txt Supports: license - Publisher installation and project documentation ↗ Checked 2026-09-21 https://github.com/anthropics/skills/blob/34040c9c568585f6929bedeaad110ad08f079624/README.md Supports: install, compatibility, access - Skills installer source formats and selective installation ↗ Checked 2026-09-21 https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md Supports: install KEEP COMPARING ## Other approaches to consider. Related by category or shared topics. These are alternatives to inspect, not a measured quality order. [### Anthropic PDF Processing ↗ Covers PDF extraction, transformation and form filling, with separate workflows for actual form fields and image-based overlays.](/skills/anthropics-pdf/)[### Anthropic PowerPoint Presentations ↗ Guides new-slide generation and template editing with OOXML validation and rendered thumbnail checks.](/skills/anthropics-pptx/)[### Anthropic Word Documents ↗ Separates new Word-document generation from editing existing OOXML, with explicit checks for tables, comments and tracked changes.](/skills/anthropics-docx/) [AI Tools ↗](/tools/)[Skills ↗](/skills/)[Agents ↗](/agents/)[MCP Servers ↗](/mcp-servers/)