Does a Life Cleric's Disciple of Life feature apply to healing effects of summoned creatures?

Question

The Life Cleric's Disciple of Life feature improves the effect of healing spells:

Also starting at 1st level, your healing spells are more effective. Whenever you use a spell of 1st level or higher to restore hit points to a creature, the creature regains additional hit points equal to 2 + the spell's level.

Does Disciple of Life apply to the healing provided by creatures summoned by spells?

For example, if the Life Cleric casts Summon Celestial and the Celestial uses its Healing Touch, would that benefit from Disciple of Life?

The same would presumably apply to spells such as Conjure Celestial (Unicorn's Healing Touch) or Conjure Woodland Beings (Dryad's Goodberry).

Answer 1

The healing bonus only applies to the cleric's own healing spells

You have the relevant text right there

Also starting at 1st level, your healing spells are more effective. Whenever you use a spell of 1st level or higher to restore hit points to a creature, the creature regains additional hit points equal to 2 + the spell's level.

The text explicitly refers to the cleric's own healing spells ("you"). The healing spells that summoned creatures use are theirs, not those of the cleric. When such a creature is casting a healing spell or using a healing effect such as Healing Touch (not even a spell), it is not the cleric casting or using a healing spell.

Answer 2

It Shouldn’t Apply, Even if Just for Balance Reasons

Whenever you use a spell of 1st level or higher to restore hit points to a creature

Very interesting, as you are using a spell of 1st level or higher and your goal could be to restore hit points to a creature when you summon something like a unicorn. When the unicorn heals a target using its ability, it's only doing so because of the summoning spell you cast that brought it into being, theoretically meeting the requirements of this ability.

There are some pretty strong arguments against this interpretation—that a summon spell isn't a "healing spell" or that there is no transitive quality for something like this, that only spells which directly heal a target would apply for the ability.

"Healing spells" aren't some defined term, so a spell that has the end result of healing someone seems like it could be considered under that umbrella. Proving that there is some idea of transitive healing between the spell and the conjured creature healing someone would be harder, but it seems just as hard to conclusively say they wouldn't count.

One very important consideration is that this also opens up the single summon spell to trigger this ability multiple times with something like the dryad's 3/day goodberry, with each casting affecting up to 10 creatures (10 berries). So a single 4th-level conjure woodland beings with this interaction could heal something like 210 hit points! And at 7 HP per berry which each last 24-hours, this would even be useful in combat as a potion of healing substitute.

With those considerations in mind, I think rules-wise this would be fine to allow but that the balance issues shouldn't be ignored.