The other posters are absolutely right on about cabbies and directions. However if you do provide a street address, the street it is on is usually given first and then the cross streets it is between is given next. Cab drivers rarely seem to understand addresses given that way anyway. In your Oasis example, they often would not even know what Machu Pichu was let alone that there are 2 of them, which seems really odd to me since it is a fairly well-known restaurant.
The part I really wanted to add to this discussion is that the last time I was there the cab driver I had didn't know Oasis, the street addresses or Machu Pichu. At first, he didn't even seem to know what Kentucky Fried Chicken was or KFC. BTW, the KFC on Paseo Colon is impossible to miss just head down the street and you will see it on your right (look for the Colonel sitting on a bench out front

). You can walk it from there. Anyway, finally the cabbie seemed to understand and said "Ah, Pollo de Kentucky". I always thought they didn't translate brandnames like that. Working with cabbies in SJ can be a real challenge. It can frustrate you or you can just go with the flow and look at it as a new experience that is part of what makes being in CR different and unique.