When education leaders and others discuss staffing challenges in K-12 schools, they often focus on teacher shortages. In response, policymakers across the country have launched a range of initiatives to increase the supply of teachers. These kinds of initiatives may help attract more people to teaching. But they address only part of the problem. To strengthen the quality of the teacher workforce, schools and districts need more than adequate applicant pools. They also need to make good hiring decisions. But making good hiring decisions presents its own problems. In this research brief, the authors describe a low-cost tool for assessing job candidates that can help inform and potentially improve teacher hiring decisions. The tool is a short, supplemental assessment completed by professional references. It was developed during a decade-long partnership between CALDER and Spokane Public Schools (SPS). Several CALDER studies suggest that the tool, through just a few questions, can provide useful clues about an applicant's potential to succeed and stay in the classroom. These studies also suggest that, despite its promise, implementing the tool presents practical challenges for schools and districts.