What does ID bring to the tool box? How does it make observations faster, cheaper or more accurate? How does ID simplify calculations or make predictions more accurate?
If the 'designer' showed up tomorrow morning that would be of no more use to 'science' than knowing there's a mechanic named George would help you fix a broken alternator in your car. And if the 'designer' did show up, how could you tell using anything other than the scientific method if the designer were real or a fraud.
The scientific method is demonstrably successful as it is responsible for the entirety of human infrastructure. Without introducing the concept of design or designer there is every reason to believe that if such a designer exists the normal process of investigating the natural world would eventually discover it, assuming the designer to exist as part of the natural world.
What does ID bring to the table that is useful and warrants it's inclusion in the toolbox of scientific method? I'm talking strictly about utility in the same way the laws of thermodynamics allow accurate calculations of heat loss or QED allows for extremely accurate predictions of quantities like the anomalous magnetic moment of the electron, and the Lamb shift of the energy levels of hydrogen or Koch's postulates which provide a framework for associating pathogenic organisms with disease.
Feynman, Richard (1985). "Chapter 1". QED: The Strange Theory of Light and Matter. Princeton University Press. p. 6.