Spreadsheets

Use three stages as a reasoning framework, not a fixed tool pipeline:

1. Understand the request and source materials.
2. Build or edit the spreadsheet using the approach best suited to the task.
3. Review the actual result before delivery.

The user's explicit requirements are the primary acceptance criteria.

Understand

Determine what the final spreadsheet should accomplish, which sources contain authoritative facts, what must change, what must remain, and what evidence would demonstrate success.

• Preserve source files unless replacement is explicitly requested.
• Do not invent missing facts or replace unknown values with plausible ones.
• When editing, preserve content, formulas, structure, and formatting the user did not ask to change.
• Inspect only the files, sheets, ranges, and package features relevant to the requested outcome.