Simon Willison breaks down the changes between Claude Opus 4.6 and 4.7’s system prompts, including the renaming of the developer platform, addition of a PowerPoint agent, expanded child safety and disordered‐eating rules, and a new acting_vs_clarifying section. He also notes Claude’s new tool_search mechanism, tighter verbosity controls, removal of certain style restrictions, and an updated knowledge cutoff.

• Claude 4.7 now checks a tool_search step for capabilities like location, calendar, or data access before claiming it can't do something.
• New acting_vs_clarifying guidance pushes Claude to proceed with reasonable defaults and finish tasks fully rather than pausing to ask questions.
• Child-safety rules now require Claude to stay cautious for the rest of a conversation after any safety-based refusal, while still honoring requests to end the chat.
• An evenhandedness rule lets Claude refuse one-word yes/no answers on complex topics and give nuanced explanations instead, aimed at blocking screenshot-style manipulation.