We demonstrate a hybrid integrated frequency-agile laser based on an InP RSOA and an E-DBR manufactured with a wafer-scale lithium niobate-on-insulator process. Achieving high output power greater than10 mW, kHz linewidth, and greater than 10 GHz tuning range with tuning efficiency ~550 MHz/V, it offers unprecedented agility and efficiency, surpassing previous limitations in frequency-tunable laser systems.