1. A system for evaluating a plurality of proposed states for a storage system that provides service to a plurality of workloads, the system comprising: computer hardware configured to: access a state tree comprising a plurality of nodes arranged in a plurality of hierarchical levels comprising at least first and second levels, the first level comprising a start node representing a current state of the storage system, the second level comprising a plurality of proposed nodes, each proposed node representing a proposed state of the storage system produced by a set of actions associated with the proposed state that changes the current state of the storage system to the proposed state, wherein: each proposed state comprises an associated set of storage-system configuration settings, and at least one service level objective (SLO) comprising a target value of a hardware or software attribute of the storage system is specified for each workload; receive new planner information comprising at least one new configuration certification to specify that a set of storage-system configuration settings achieve one or more SLOs for the workloads of the storage system; remove at least one proposed node in the state tree based on the new planner information, the removal to: determine that at least one workload of the storage system has a specified SLO that matches an SLO specified in at least one received configuration certification, and remove at least one proposed node from the state tree that represents a proposed state with an associated set of storage-system configuration settings different from the set of storage-system configuration settings of the at least one received configuration certification.