Upvote:2
'A Soldier's Duty' by Rokossovsky himself doesn't contain anything about his WWI service.
The general information is that he was a very brave volunteer, who joined KDP on the outbreak of the war and reached the rank of NCO through the line of some great (for a soldier) exploits - sometimes, always like 'brigadier Gerard'.
According to Rokossovsky himself, his contemporary in the Regiment - Ivan Tulenev, one of only 7 people in History who ever had St George's Crosses of all 4 classes and the future Soviet '4 star general', - was even more brave then he himself was. [1]
If you need any technicalities, so to say?
Upon joining KDP, Rokossovsky almost immediately went scouting, and made accurate observation of German units whereabouts. That proved to be of great help to Russian superior commanders - and he received St George's Cross 4th class. [1]
Next time he volunteered to No Man's Land with 3 other dragoons, and managed to kill or take prisoners the entire German FOP. After a full day of heavy artillery bombardment they managed by night to extract all the prisoners and get them to HQ of their Regiment. St. George's Medal 4th class. [1]
And so on, and so forth...
[1] Sources: Various Russian Language documents stored within the Russian State Archive for Military History (РГВИА)