An abrasive rotary tool includes a tool shank defining an axis of rotation for the rotary tool, and an abrasive external working surface. The abrasive external working surface includes a resin, and a plurality of porous ceramic abrasive composites dispersed in the resin, the porous ceramic abrasive composites including individual abrasive particles dispersed in a porous ceramic matrix. At least a portion of the porous ceramic matrix comprises glassy ceramic material. A ratio of the average porous ceramic abrasive composite size to the average individual abrasive particle size is no greater than 15 to 1.