How to get the most out of Opus 5.5 in Claude and Claude Code

Getting the most out of Opus 5.5 in Claude and Claude Code

Anthropic's official guide covers using Opus 5.5 in Claude and Claude Code, spanning prompts, long-task control and result checks. It recommends stating clear completion criteria, setting in CLAUDE.md the conditions for continuing versus stopping to ask, keeping task lists in files, and checking the evidence sub-agents submit.

Why it matters: Anthropic's guide breaks long tasks into completion criteria, stop conditions and result checks, using file lists and sub-agent evidence to cut missed steps.