I think the intent of the charm is the other way around. It has three effects.
Passively, whenever you create, modify, or repair something, you do so five times as fast. This is an always on effect that applies to anything you do described by those verbs. It would apply to cooking a meal, computer programming, painting a picture, or concocting an alchemical tonic. They're all the act of creating something, so they all get accelerated.
When you create, modify or repair something complicated and mechanical, you do so ten times as fast. As above, this is an always on effect.
Optionally, you may also choose to spend essence or willpower to get an additional effect, conjuring tools from the Wicked City, removing the usual penalties of not having the right tools for the job. This is not required to get the acceleration of the first two effects; it's an additional benefit you can choose to take advantage of if you don't have the appropriate tools to hand.
If you do have the required tools, for example you're cooking a meal in a well equipped kitchen, the charm just means that the food preparation and the cooking time is supernaturally accelerated five fold, and any watching chefs get very confused about how it's possible.