It is absolutely ridiculous that he reads the screwdriver as if there is some kind of screen on it. It is also ridiculous that a screwdriver has sensors and, well, other tricorder like functions.
Most ridiculous of all is that the story never needs the screwdriver to do these things. It is easily written around with the same result obtained.
I loved the sonic screwdriver as an aesthetic; a way to have the Doctor appear high-tech and other-worldly when in fact all he is doing in the story is opening or closing something, or turning something on and off.
The screwdriver should be should be used just for that: make things lock and unlock, turn on and off, the end.