Do items that affect an Artificer's spell attack modifier also affect the Steel Defender's actions that use said spell attack modifier?
As an example, my current level 4 Artificer has
- +4 INT
- +2 Prof bonus
- +1 from an All-Purpose Tool
- +1 from the Enhanced Arcane Focus
So a +8 to spell attacks. Does this mean that Force Empowered Rend also has +8?
See Steel Defender's Force Empowered Rend Tasha's Cauldron of Everything (pg. 19):
Melee Weapon Attack: your spell attack modifier to hit, reach 5 ft., one target you can see. Hit: 1d8 + PB force damage.
Artificer's Enhanced Arcane Focus Infusion Tasha's Cauldron of Everything (pg. 21):
While holding this item, a creature gains a + 1 bonus to spell attack rolls. In addition, the creature ignores half cover when making a spell attack. The bonus increases to +2 when you reach 10th level in this class.
All-Purpose Tool Tasha's Cauldron of Everything (pg. 119):
Wondrous item, uncommon (+1), rare (+2), very rare (+3) (requires attunement by an artificer)
While holding this tool, you gain a bonus to the spell attack rolls and the saving throw DCs of your artificer spells. The bonus is determined by the tool's rarity.