How would you design the perfect silenced pistol?

Been looking at different designs and I like the concept things like the Welrod and PB pistol, as well as the DeLisle Carbine.

I like the design of the Welrod being basically a straight pull bolt action to ensure all of the gas can only escape through the supressor instead of also being able to vent out of the breach. But I also like the ability to have semi auto fire.

The pistol should be able to function as an actual pistol instead of just a silent execution weapon, so a silencing method that compromises the effectiveness of the gun should be avoided.

I'd also like a method that doesn't degrade like the welrod's supressor does, since it's made out of leather and rubber like some kind of BDSM gear, the DeLisle uses an all metal supressor that only needs to be cleaned.

Is this an achievable goal?