If people lived on a desert island, it would not be a desert island. It would be an inhabited island.
If this is a deserted Island this is strictly a practical consideration. If this is an Arctic Island you will need heavy Arctic clothing If this is a tropical Island you will need clothing to protect you from insects, damage from the environment depending on what you need to do to survive. Shoes for example. Of course a Desert island would be different ;)
If you were stranded on a deserted island and could only choose one tool for survival, would you prefer a diamond or a hammer?
A desert island is an island that is uninhabited by humans. Therefore you would not find people on a desert island.
it means you have to write an essay saying that if you were lost on a desrted island what would you do?
With a population of about 1 million people, Tenerife would hardly be considered a 'desert' island. Parts of the island have low rainfall and would have a desert climate.
hot, dry cliamte
A desert island is one with nobody living on it. (from 'deserted' rather than the region 'desert'). Hence it can look like anything, although usually it'll be inhospitable (No fresh water or no trees or something like that (there's usually a reason for nobody to live there)) It could just be a strip of sand.
A boat... Cruise Ship... A chainsaw...
Water, and the brain power to use the resources that you find.
Water, food, boat, knife, gun, phone
A desert island is not specific to any climate; however it is unlikely that a desert island would have a desert climate... because it's an island; a chunk of land in the middle of water. The desert in desert island means that no-one lives there... it's deserted. Islands in the Arctic and Antarctica could be considered deserts, but one usually connotes desert islands as having tropical climates.