This paper describes the design of a tool to support learners in simulation-based discovery learning environments. The design redesigns and extents a previous tool to overcome issues that came up in a classroom learning setting. The tool focuses on supporting learners with experimentation to identify or test hypotheses. The aim is not only to support learning domain knowledge, but also learning discovery teaming skills. For this purpose the tool uses heuristics and formal methods to assess the learners experimenting behavior, and translates this assessment into feedback directed at improving the quality of the learners discovery learning behavior. The tool is designed to be part of an authoring environment for designing simulation-based learning environments, which put some constraints on the design, but also ensures that the tool can be reused in different teaming environments. After describing the design, a learning scenario is used to serve as an illustration of the tool, and finally some concluding remarks, evaluation results, and potential extensions for the tool are presented.