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This screwdriver is too small to be useful.
Literal
This screwdriver [topic-は] small-too much not-serve purpose.
~すぎる 'too much X' attaches to adjective stems (小さ + すぎる = 'too small'). When conjugated to te-form and linked to a negative outcome, it gives the 'too X to Y' structure. 役に立つ 'to be useful' literally 'to stand in the role (of something useful)' — 役 'role,' に 'in,' 立つ 'to stand — a fixed idiomatic expression for usefulness.