tablint

https://tablint.dev/v1/bazaar/table/preflight

Inspect a CSV, TSV, or XLSX spreadsheet before an agent ingests it. Detects misplaced header rows, repeated header rows, multiple tables on one sheet, merged cells, ragged rows, totals rows, formulas, hidden sheets, mixed or inconsistent column types, numbers stored as text, ambiguous dates, and duplicate or empty column names. Returns a machine verdict (clean, needs cleaning, split tables, review, or reject), the blocking problems, per-sheet structure, per-column types, and a recommended next action so the agent knows whether the file is safe to load and what to fix first.