Our Gemara on Amud Aleph weighs the ethics of whether one is obligated to inform another of a gift that is being given:

One who gives a gift to his friend need not inform him that he has given it to him, and he need not concern himself that the recipient might not realize who gave it to him. As it is stated: “And Moses did not know that the skin of his face was radiant” (Exodus 34:29); Moses received this gift unawares.

The Gemara raises an objection to this. Isn’t it written: “Nevertheless, you must keep My Shabbatot, for this is a sign between Me and you throughout your generations, that you may know that I am the Lord Who sanctifies you” (Exodus 31:13), which the Sages expounded as follows: The Holy One, Blessed be He, said to Moses: Moses, I have a good gift in My treasury, and its name is Shabbat, and I wish to give it to the Jewish people. Go and inform them of this intention of Mine. And from here Rabban Shimon ben Gamliel said: One who gives a gift of a piece of bread to a child must inform his mother of his actions, so that the child’s parents will be aware of the giver’s fond feelings for them, thereby enhancing friendly relations and companionship among Jews. This appears to be in direct contradiction to Rabbi Ḥama’s statement.

The Gemara answers: This is not difficult; this case, where one need not inform the recipient, is referring to a gift that is likely to be revealed, such as Moses’ shining face, which everyone would point out to him; that case, where one must inform the recipient, is referring to a gift that is not likely to be revealed in the natural course of events. The Gemara challenges: Isn’t Shabbat also a gift that is likely to be revealed, as the Jews would eventually be instructed with regard to the time and nature of Shabbat? The Gemara answers: Nevertheless, its reward is not likely to be revealed. Therefore, God told Moses to inform the Jews of the gift of Shabbat and its reward.

Let us follow the thread of this discussion:

1. At first Gemara considers that one is not obligated to inform of gift as we see from Moshe’s shining
2. Then we see from Shabbos that one is obligated
3. From the dialectic of the contradiction the Gemara concludes one is obligated to inform when it will not be apparent
4. A final distinction is made, that even if the gift will become apparent, if an aspect of it, such as the reward for keeping Shabbos is not apparent, then one still must inform

What is potentially problematic in not informing a person about a gift?  Rashi says that the person will wonder where the gift came from.  This Rashi seems to imply that even causing a small pain of confusion and doubt is not derech eretz. Benayahu expands on this. He asserts that Rashi did not mean this alone. Rather, it is important to know the REASON for the gift, such as if it came as repayment for a favor or as an act of unconditional love.  There is support for this idea from what Rashi says later, “Tzarich”, who mentions that when you let the parents know that you gave their child a treat, this will promote “friendship and love in Israel” (I guess once upon a time, parents did not resent strangers giving their kids candy!), basically shalach manos out of season.  It is this last point I want to focus on.

There are persons who are averse to intimacy, and even when doing a kindness, shy away from making their intentions explicit.  They might buy flowers for shabbos or prepare a meal for their loved one, but not state warmly their intentions.  This Gemara according to Benayahu and Rashi reminds us that part of the act of kindness, is stating your intentions warmly, as that magnifies the feelings.