I've lived in Houston for 23 years and I frequent the Northwest Harris County Public Library weekly, yet I had no idea this pocket park even existed! There is no sign announcing it's presence and it sits behind the library. The only way I found out about this park was by visiting the Precinct 3 Parks and Recreation website.
Having said that, this park is nothing to write home about. It's a nice place to eat a snack and read a book, but it's very small. It's not a hiking destination, but more of a place to hangout outdoors or to walk the dog.