I solved this as "I have a small friend." Considering friendship can't exactly be "small", the smallness only applies to the person, and you would say someone is small as much as say that someone is short, right?
As I can see in the vocabulary, byka is small - mība is short :)
I.e. with a sword there's a difference by saying "a short sword" or "a small sword" - if using small, it's understood as if the exact proportions of the sword are kept but it's not as big as a regular sword... like with a miniature car - did this help?