Debt service coverage is net operating income — or, on many investor programs, market or in-place rent — divided by the annual payment. A 1.00 DSCR means the property pays for itself. Above that, you have cushion. Below it, you are asking the lender to believe a story.
Personal income does not raise the ratio. That is the feature: a borrower with complicated taxes can still add a rental if the building carries the note. It is also the limit. A beautiful house that does not rent for the payment is not a DSCR deal at that price.
Before you write an offer, divide realistic rent by the payment at the leverage you want. If the math is tight, the fix is price, rate, or a larger down payment — not a longer personal financial statement.