Wondrous item, uncommon (+1), rare (+2), very rare (+3) (requires attunement by an artificer)
As per All-Purpose Tool this simple screwdriver is able to transform into the variety of tools; as an action, you can even touch easily an item and transform it into any kind of artisan’s tool of your choice (you can see the “Equipment” chapter in the PHB for a list of artisan’s tools).
So whatever from a tool takes, you’re almost proficient with it. So while holding this specific tool, you can easily gain a bonus to the spell attack rolls and even the saving throw DCs of your artificer spells. Here the bonus has been determined by the tool’s rarity.
So, as an action, you have the capability to focus on the tool for channel your all creative forces. You can select a cantrip which you do not know from any class list. For almost 8 hours, you can cast that specific cantrip, and even it counts as an artificer cantrip for you. Al though once the property has been used, it can not be used again unless until the next dawn.