Making decisions based on visual input is challenging because determining how the scene should be split into individual objects is often very difficult. While previous work mainly considers decision making and visual processing as two separate tasks, we argue that the inherent uncertainty in object segmentation requires an integrated approach that chooses the best decision over all possible segmentations. Our approach over-segments the visual input and combines the segments into possible objects to get a probability distribution over object compositions, represented as particles. We introduce a Markov chain Monte Carlo procedure that aims to produce exact, independent samples. In experiments, where a 6-DOF robot arm moves object hypotheses captured by an RGB-D visual sensor, our approach of probability distribution based decision making outperforms an approach which utilises the traditional most likely object composition.