This shortcut should work out of the box if you are using the apple watch to log your swims.
For moth MTD and YTD : #of swims, miles, time and average pace per Paceyards variable (usually 110, 50 or 25)
For both MTD the best performance per category is displayed: yards, time, and pace. The brace is based on time and the corresponding stokes.
Day, yards, time, laps and pace
Siri is supported