Complex sentence: The Senate has little legislative power, but retains considerable powers of scrutiny and appointment as the Senate is vested with the power to advise on the appointment of members of the judiciary and independent government agencies.
Split into simpler sentences: The Senate has little power legislative-wise, but retain considerable powers of scrutiny and appointment. As the Senate is vested with the power to "advise" on the appointment of several members of the Judiciary and independent government agencies.