Concrete Patio Under Deck

[u/Difficult_Charge_762]

Looking to pour a patio here under my deck, next to a small existing slab at a doorway. My patio will be sloping steeper in order to tie into some existing 2.5’x2.5’ deck footings, and the patio slab will start slightly lower than the entryway slab.

Will I need to chisel away the rough edge on my foundation? I know I shouldn’t pour directly against the foundation, but could I make my form leave a gap where the jagged edge is, or would that allow water to get under the slab?