[DOCS] Document the difference between `ultrathink` and Thinking Mode On/Off

Agreed 👍

Reddit post about this: https://www.reddit.com/r/ClaudeCode/comments/1nyly8m/what_is_the_difference_between_thinking_onoff_and/

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Bump

I guess it's documented here now?

@uschtwill Unfortunately there is no single occurrence of /ultrathink. Maybe it's deprecated or just visuals and a gimmick. Nonetheless the prompts seem to affect the depth of thinking.

Hi @PaulRBerg and @greetclammy 👋

Thanks so much for raising this issue. We've updated the documentation to address these questions; here's a summary:

How Thinking Mode and ultrathink work together

Thinking Mode (On/Off)

• Turn thinking mode on or off via /config → sets your global default
• Note: this is a recent change; thinking mode used to be toggled on/off with Tab, but now you set it in your /config
• Thinking mode is binary: you allocate either 0 tokens (thinking mode off) or 31,999 tokens (thinking mode on) for thinking

ultrathink keyword

• A per-request override you can use in any prompt (e.g., ultrathink: design a caching layer)
• Bypasses your global configuration and enables thinking just for that request even if thinking mode is off in your /config
• Also semantically signals to Claude to reason more thoroughly, which may result in deeper thinking
• The total allocated token budget for thinking remains the same, but the keyword might signal to Claude to think more than it would if you didn't use the keyword

Clarifications:

• Only ultrathink is the special keyword that enables thinking on a per-request basis. Phrases like "think", "think hard", "think more" don't have any impact on the allocated thinking token budget.
• If you need fine-grained control over the token budget (vs. just allocating all 31,999 tokens to the thinking budget), you can set the MAX_THINKING_TOKENS environment variable. This setting takes priority over ultrathink, so if you set a lower MAX_THINKING_TOKENS threshold, ultrathink doesn't override it.

Documentation links

• Use extended thinking (thinking mode)
• Per-request thinking with ultrathink
• How extended thinking token budgets work

Thanks for flagging this and let us know if you have any other questions!

docs have been updated

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