Goal Prompt keeps the agent working until a completion condition is met. Both Claude Code and Codex take it as one line, max 4,000 characters. In Claude Code a small model re-judges the condition after each turn from the transcript alone — it cannot run commands. Draft a condition that can terminate, then format it. A goal fits work bigger than one turn with a checkable finish line; chain small goals with review between them rather than writing one giant goal. Draft Include, joined with AND — never "or", the loop takes the cheaper branch: 1. End state, not activity — "all call sites use ", no…