Fiona, in GSAK, when you choose "GPS" from the menu at the top, then choose "Send waypoints", you get a dialog box. In that box, for "You can build the waypoint name using tags" enter "%smart" (without the double quotes). Then for "Maximum characters" enter the number of characters your gps uses for waypoint ids (usually 6 or 8). Then for "Waypoint description format" enter "%name". Then click "Send".
I use GSAK, but I send to my gps from OzzieExplorer as GSAK doesn't support my gps (an MLR SP24), so though I think that's correct I have no means of testing it.
Do not go gentle into that good night.
Rage, rage against the dying of the light. (Dylan Thomas)