It is difficult to translate this really succinctly with the same meaning because in Chinese I think it includes the idea of whether or not you are a good person and also an element of whether or not you have good guanxi. So the above is my suggestion, and you can include or not the bit in brackets depending on what balance you want between being succinct and being accurate.
It might be tempting to translate it as the common phrase - it is not what you do, but who you know - but I think this would be wrong as this really emphasises the social status of the people you know, which is not what this Chinese phrase is about, I think.

Like Simon said, the term 做人 can be very complicated. In this context, it sounds like 做人=尔虞我诈，做人圆滑，both of which are pretty negative. Soft skills or people skills fit well in the self explanation. But either of them or Simon's version carry the negative tone.

In the Chinese society, those who know how to behave are much better rewarded than those only know how to do things well. For most of the time, doers are losers, and talkers are winners. Ironic but true.