Q: Is the debtor considered poor, and thus eligible to Zakāt funds?
الجواب حامدا ومصليا ومنه الصدق والصواب
A: If the individual’s non-essential items do not cover the qualifying debts or do not reach the nisāb after covering qualifying debts then that person is considered poor and is eligible to receive zakāt. It is not the relative ability to pay that determines eligibility but rather whether the recipient has reached the nisāb of eligibility or not. Further details on the criterion of eligibility can be seen at the following link:
As for how much one can give an eligible recipient, it is reprehensible to give the recipient an amount that would clear his/her debts by more than the nisāb resulting in the recipient being liable to pay zakāt him/herself.