Most infants are well hydrated at birth because of the placenta (nature's way of ensuring the baby is fine while mom is recovering and breastmilk volume is established). Urine output usually exceeds fluid intake for the first 3-4 days after birth. Small calorie-rich colostrum feedings of less than a teaspoon to a maximum of 3 teaspoons are the appropriate amount for the newborn's stomach which can hold only about this much on day one. Why would we expect baby to take in more than this? Yet, many of us do just that because we are comparing this feeding to that of an older infant. Encouraging more by bottle will result in overfeeding and practically guarantees baby will spit up. It is also enough to prevent low blood sugar in term infants. It is also easy to manage while the infant learns to coordinate suck, swallow and breathing. It is enough to satisfy their hunger and thirst as well as meeting the sucking needs of the newborn which are greater than the amount of food. This sucking is also what helps bring in the mother's more voluminous mature milk.
As you can see, it's perfect!