Teacher evaluation is at the center of current education policy reform. Most evaluation systems rely at least in part on principals' assessments of teachers, and their discretionary judgments carry substantial weight. However, we know relatively little about what they value when determining evaluations and high stakes personnel decisions. Using unique data from an independently managed public charter school district, I explore the extent to which autonomous school administrators' formative evaluations of teachers predict a variety of future personnel decisions. I also assess the extent to which their evaluations predict alternative measures of teacher performance, including student and parent evaluations of individual teachers in the same and future school years. I find that formative midyear ratings--shared by administrators with teachers--clearly differentiate between teachers and are strongly associated with end-of-year dismissal and promotion decisions. I use an exploratory factor analysis to identify four distinct components of administrators' feedback to teachers and show that different components predict different types of personnel decisions in schools. In addition, different components predict different teacher performance measures. The results suggest the importance of accounting for multiple aspects of teachers' work in evaluation systems that are meant to inform multiple types of personnel decisions.