How can you optimize prompts migrating from Sonnet 4.6 to Sonnet 5?

Start by testing existing Sonnet 4.6 prompts largely as-is, since Anthropic's own guidance indicates Sonnet 5 performs well out of the box on them - the goal is a targeted tuning pass on known behavior shifts, not a full prompt rewrite from scratch.

Review response-length expectations specifically, since Sonnet 5 calibrates verbosity to perceived task complexity rather than a fixed default, and adjust length-control instructions only where a specific product's output-length requirements actually diverge from that adaptive behavior, rather than assuming every prompt needs new length constraints.

Where you observe shallow reasoning on genuinely complex requests, raise effort to high or xhigh as the primary fix, reserving prompt-level step-by-step-style instructions specifically for cases where effort is constrained by a hard latency requirement and can't simply be raised.

Remove any prompt language written around the old manual thinking-budget model, if present, since that configuration no longer applies, and replace it conceptually with effort-level guidance instead, testing at medium effort before assuming high is required, since Sonnet 5 is reported to be meaningfully more capable at medium effort than Sonnet 4.6 was at any comparable setting.