`define-goal`: Clarify the Goal First, Then Let the Agent Take Action

This article introduces OpenAI's curated Skill `define-goal`: it is used to refine vague intentions into specific, measurable and verifiable goals before coding, and call `get_goal/create_goal` again in accordance with quality standards. Based on the official SKILL.md documentation, the article explains the workflow, comparisons between good and bad goals, Codex installation (via `$skill-installer`), and the method of enabling it in tools such as Cursor/Claude Code through the SKILL.md directory. It also reminds that this skill only performs goal definition and does not manage long-cycle execution deliverables.