Table schema:
CREATE TABLE staff (staff_id VARCHAR, staff_first_name VARCHAR); CREATE TABLE problems (problem_description VARCHAR, reported_by_staff_id VARCHAR)

Question: Give me a list of descriptions of the problems that are reported by the staff whose first name is Christop.
SQL: SELECT T1.problem_description FROM problems AS T1 JOIN staff AS T2 ON T1.reported_by_staff_id = T2.staff_id WHERE T2.staff_first_name = "Christop"