CGM-Tool is a computer-aided support for modeling and reasoning on constrained goal models. It is a standalone application written in Java and its core is based on Eclipse RCP Framework. The tool provides diagrammatic modeling, automated well-formedness analysis and reasoning functionalities on constrained goal models. Under the hood, CGM-Tool encodes the diagrammatic model into SMT formula and run the encoding result on OptiMathSAT solver, it then parse the solver outcome to display the result directly on the diagram as well as in tabular and pdf document form.