If i were stranded on a desert I would bring a lighter, a tarp, and a knife. To survive humans need water, food, and protection against the weather and animals. There are many possibilities for thing you can bring but I believe that the three items I chose would give you the best chance of surviving.
The first thing I chose was a lighter. I would choose one that would not run out of fuel easily. The lighter would serve a couple of purposes. First, I would use it to start fires to keep warm. In the desert it can at times get really cold at night. Another purpose of the lighter would be to start a cooking fire or a signal fire. Meat needs to be cooked to eat and so do other foods. Boiling water can also purify it. A signal fire could alert planes and helicopters that I need help. In addition to all of these advantages a fire will help scare away animals at night.
The next item I would bring is a tarp. With the tarp I could make a shelter to protect me my the elements. This is important because being out can be a risk to your health. The tarp would protect me from the sun. Another use would be to collect dew or water. Rainwater is generally safe to drink so if the tarp is up and the corners up a little it will make a kind of bowl to collect water.
The last item I would bring is a knife. It could be used as protection against animals. The knife can also be used to kill animals for food. Another use is to cut down plants and sticks for a shelter and food. There are an large number of uses for a knife.
In conclusion, I believe the best items to be stranded with are a lighter, a tarp, and a knife. With these tools you would have the best chance of surviving. You can cook and cut up food, collect water, and start fires.