Tasha's Cauldron of Everything (p. 119) includes a magic item called the all-purpose tool, whose description states the following:
This simple screwdriver can transform into a variety of tools; as an action, you can touch the item and transform it into any type of artisan's tool of your choice [...]
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.
When it states that you need to hold the tool to gain this benefit, does this also imply that I need to use it as my spellcasting focus as well? Or can I just hold it with one hand and use the other hand to hold another spellcasting focus, and still gain this benefit?