Dumping a 50k-row spreadsheet into an LLM context is expensive and usually unnecessary. Most tasks need surgical access ie: find a region, profile its structure, read a filtered slice.

SpreadsheetMCP is a Rust MCP server with 20+ tools that let agents discover -> profile -> extract without burning tokens on cells they don't need. Supports xlsx/xlsm, VBA inspection, formula tracing, what-if analysis via forks, and headless screenshots via LibreOffice.

In my testing, agents handle sweeping refactors both in formulas and formatting quite effectively!