Figure 2: LifecycleSkillBench construction and evaluation. Public tasks, tools, and rules support re-
producible environmental changes, paired affected and capability-retention tasks, and persistent up-
date histories. The evaluated method receives the change description, pre-update Skill, and available
evidence. The evaluator separately stores test tasks, reference outcomes, and recoverable historical
versions, and reports recovery, retention, error propagation, and execution cost.