Why do I need to measure Noise Parameters when designing a receiver?

To design a receiver, engineers will need to select transistors for the design. You could obtain a sample of the transistor and perform noise parameter measurements while possibly setting the transistor to different power consumption settings and also varying the temperature. This gives the engineer complete information on how to select "matching" components (inductors and capacitors) that go at the input of the transistor to obtain the lowest noise figure and ultimately allows him to design the best performing receiver.