Explain
Use this as Codex's equivalent of /up:e.
- If the user named a file, error, diff, or behavior, inspect it before explaining. If they did not, infer the most recent clear topic and state what you selected; ask once only if no target is clear.
- Lead with the mechanism that answers the question. Assume the reader only vaguely remembers surrounding context.
- Give evidence in plain language, normally one to four paragraphs. Avoid doc dumps, invented terminology, and unexplained shorthand.
- End with up to three deeper follow-up threads only when they would add real value.