In this paper we discuss the design of result verification in desktop grid systems. In this design, correctness and performance are considered as important issues. To guarantee the correctness of work results, sabotage-tolerant mechanisms have been mainly used, such as voting-based schemes and trust-based schemes. However, these mechanisms result in low scalability and high computation delay because they can not cope effectively with dynamic environments. In this paper, we propose a Sabotage-Tolerant Scheduling for Result Verification (STSRV), which is based on mobile agent technology. In STSRV, mobile agents are used to check periodically the credibility and availability of each volunteer. Using credibility and availability information, our desktop grid system can provide correctness of work results without a huge increase in the computation delay caused by result verification. Additionally, simulation results show that STSRV increases turnaround time for works from the viewpoint of credibility and availability, and thus enhances the overall performance of our desktop grid systems.