The natural way to say “the screwdriver is broken” in Chinese is: 螺丝刀坏了。
Luósīdāo huài le.

Breakdown

  • 螺丝刀 = screwdriver
  • 坏了 = broken / not working anymore

Useful alternatives

  • 螺丝刀断了。 = The screwdriver snapped / broke in half.
  • 螺丝刀不能用了。 = The screwdriver can’t be used anymore.

Quick usage

If the tool is damaged in general, 坏了 is the most common and natural choice. If it physically snapped, 断了 fits better. If you want, I can also show you how to say this in both simplified Chinese and pinyin only.