Your version of SDK tools has nothing to do with the parameters
input can understand or execute. Input is a binary in Android OS which can be run independently without requiring any set of external tools such as ADB.
The reason you receive the error "
Error: Unknown command: touchscreen" is because you're running an Android version earlier than Android 4.1.1. You would already notice that in the
input usage you posted, the binary entertains only two parameters i.e.
In Android 4.0.x, the
input command's usage remains the same as the one you posted. In fact, even Android 2.3.7 has the same input command's usage. (See com.android.commands.input.Input on GrepCode for comparison of command's usage between Android versions.)
It was Android 4.1.1 which introduced
swipe parameter with usage,
usage: input ...
input text <string>
input keyevent <key code number or name>
input tap <x> <y>
input swipe <x1> <y1> <x2> <y2>
See the source code for more.