Anthropic Revealed Their Secret Guide to Mastering Opus 5.5

Anthropic just dropped an official guide on prompting Claude Opus 5.5, and some of your old habits might be wasting tokens now. In this video I speedrun the 8 biggest takeaways, including the default setting that quietly changed and the prompt line you should probably delete. By the end you'll get better answers out of Opus 5.5 0:00 - Anthropic's Opus 5.5 prompting guide 0:21 - Tip 1: The new default effort level 1:47 - Tip 2: Drop the "think carefully" instructions 3:13 - Tip 3: Make Claude check every source 4:37 - Tip 4: Separate your request from pasted content 5:14 - Tip 5: Why Claude can seem silent 5:57 - Tip 6: A finished reply isn't a finished task 6:56 - Tip 7: Give Claude a clear design direction 7:41 - Tip 8: Help Claude read small details 8:15 - Final thoughts