Anthropic shares prompt guidance and operational tips for Opus 5.5

Anthropic published new operational guidance written by Addy Osmani on how software developers and users can get the best results from its Claude Opus 5.5 model. The guide focuses on managing long autonomous runs, writing effective instructions, and checking output quality when using the model in coding and everyday applications.

According to the publication on claude.dev, Opus 5.5 is designed to perform extended multi-step tasks with minimal human intervention once given an explicit definition of what completion looks like. Notably, the guide advises users to strip out common prompting phrases like "think carefully," because the AI now automatically calculates its reasoning time before answering. Adding those extra commands can actually delay initial replies without improving accuracy.

The documentation also outlines techniques for controlling autonomous software agents, such as directing the system to split massive code audits across parallel subagents or setting explicit rules for when to pause for human approval. For visual design tasks, the guide suggests explicitly listing unwanted aesthetic defaults rather than using vague requests for originality.

As artificial intelligence models gain greater autonomy to complete complex projects over extended periods, user management strategies are shifting from step by step steering toward clear goal setting and defensive guardrails. This evolution raises an important question for developers: as AI systems take on broader end to end responsibility with fewer human checkpoints, how will engineering teams ensure long term oversight without creating new operational bottlenecks?