diff --git a/demo/include/demo/cost_estimator.hpp b/demo/include/demo/cost_estimator.hpp
index 1b6c441..eaf442f 100644
--- a/demo/include/demo/cost_estimator.hpp
+++ b/demo/include/demo/cost_estimator.hpp
@@ -11,6 +11,9 @@
 
 namespace demo {
 
+/**
+ * @brief The CostEstimator estimates a cost quantity for a given command to be used as a decision heuristic.
+ */
 struct CostEstimator : public arbitration_graphs::CostEstimator<Command> {
     struct Parameters {
         /// @brief The radius of the neighborhood around the end of the path that is checked for dots.
@@ -22,6 +25,13 @@ struct CostEstimator : public arbitration_graphs::CostEstimator<Command> {
             : environmentModel_{std::move(environmentModel)}, parameters_{paramters} {
     }
 
+    /**
+     * @brief Estimate the cost of a command.
+     *
+     * The cost is estimated using two metrics: The steps per dot along the path and the dot density at around the end
+     * of the path. This is done to balance the short-term gain by following a path with many dots and the long-term
+     * gain by moving towards a promising area.
+     */
     double estimateCost(const Command& command, bool /*isActive*/) override;
 
 private: