spreadsheet-proof-gate

Spreadsheet Proof Gate

Use this skill when you must modify, create, or validate an Excel workbook and the result must be proven against a user specification rather than merely described.

This skill combines:

• workbook discovery and identity confirmation
• pre-edit structure auditing
• safe workbook editing
• deterministic post-write verification from disk
• a machine-checkable pass/fail checklist for every requested criterion
• a hard finalization gate that rejects completion when any required criterion is unmet or unreconciled

This is a workflow skill. It does not require a specific editor, but it does require a direct Python verification pass with openpyxl before you report success.

When to use

Use this skill when any of the following are true:

• the workbook path must be discovered
• multiple similar Excel files may exist
• the user requires exact sheet names, columns, counts, or samples
• the task edits an existing workbook
• a delegated agent may perform spreadsheet work
• prior summaries are inconsistent or not trustworthy
• exact post-edit workbook state matters
• you must prove that mandatory criteria were satisfied

Core rule

Never finalize from narrative summary alone.

A workbook task is only complete when:

1. the target workbook was identified from the anchored workspace path
2. pre-edit structure matched the intended operation
3. the edit was performed on the correct file
4. the saved workbook was directly re-read from disk
5. every requested criterion was checked in a deterministic verification report
6. each criterion is marked as one of:
   • PASS
   • FAIL
   • UNAVAILABLE-IN-SOURCE
7. any non-pass result is explicitly reconciled before finalizing

If any mandatory criterion is still FAIL, do not declare success.

If a criterion is UNAVAILABLE-IN-SOURCE, only finalize if:

• the source workbook truly lacks the needed input,
• you state that clearly,
• and the user request did not require inventing unsupported data.

Workspace anchoring rule