It all depends on you and what pet you will take care of. Different things may be required for a dog than for a rabbit or turtle. However, you should require the pet's owner to take his belongings with him (bedding, blanket, toys, leash, collars, harnesses, muzzle, litter box, litter, scratching post, health book, water and food bowls, etc., cage, terrarium), and also any things that will remind him of home (the owner's worn clothes, food, etc.). You can also wish that all animals you adopt are neutered/neutered, vaccinated, dewormed, non-poisonous (in the case of spiders), etc. It is your decision. You can also require prior familiarization with the pet to know if it will not cause problems and the care will be as expected. In addition, all this information can be included in the description of the care offered.