Definition of Agentic Task An agentic task is a composite task performed by an AI agent through a structured combination of multiple subtasks, where each subtask represents a distinct part of what needs to be accomplished and is fulfilled by an appropriate reusable skill. An agentic task can be represented as $\tau=({T}\_{\tau},{S}\_{\tau},{R}\_{\tau},{M}\_{\tau})$, where $\tau$ (agentic task) denotes the complete task to be performed, ${T}\_{\tau}={t_1,t_2,\ldots,t_n}$ (subtask set) contains the subtasks that collectively constitute the task, ${S}\_{\tau}={s_1,s_2,\ldots,s_m}$ (skill set) contains the reusable skills available for fulfilling those subtasks, ${R}\_{\tau}$ (execution relations) specifies how the subtasks and their corresponding skills are organized and performed sequentially, iteratively, recursively, or through an appropriate combination of these patterns, and ${M}\_{\tau}$ (evaluation metrics) contains the task-specific measures used to determine whether intermediate results and the overall task outcome satisfy the expected requirements. For each subtask $t_i$ (subtask), an appropriate skill $s_j$ (reusable skill) may be selected from predefined skills or dynamically engineered during task execution when an existing skill does not adequately address the subtask. ...