skill 和外掛每輪占多少 token？

Skills use progressive disclosure to manage context efficiently. ChatGPT and Codex start with each skill's name and description, then load the full SKILL.md instructions when they decide to use that skill. In Codex, the initial list also includes each skill's file path.

To avoid crowding out the rest of the prompt, this list uses at most 2% of the model's context window, or 8,000 characters when the context window is unknown. If many skills are installed, Codex shortens skill descriptions first. For large skill sets, Codex may omit some skills from the initial list and show a warning.

/usage — View account token usage or use a rate-limit reset. Inspect daily, weekly, or cumulative ChatGPT token activity from inside the TUI.

In a regular session, skill descriptions are loaded into context so Claude knows what's available, but full skill content only loads when invoked.

Every skill in the skill listing adds to your context on every turn, whether or not Claude ever uses it. Run /skill-doctor to see what each of your skills costs and how often it gets used, so you can decide which ones to turn off.

The budget scales at 1% of the model's context window. When the listing overflows, Claude Code drops descriptions starting with the skills you invoke least, so the skills you use most keep their full text.

Skills load on-demand only when invoked, so moving specialized instructions into skills keeps your base context smaller.