Exploring the Evolution of Claude's System Prompts in Opus 4.7

Anthropic stands out as the only major AI lab openly publishing system prompts for their chat systems, tracing back to Claude 3 in July 2024. With the recent release of Opus 4.7 on April 16, 2026, several updates have been made to the Claude.ai system prompt since Opus 4.6. Notably, the 'developer platform' has been rebranded as the 'Claude Platform,' and new tools like 'Claude in Powerpoint' have been added to the list of Claude tools. A significant expansion in the child safety section now mandates extreme caution in subsequent conversations after a refusal based on child safety.

Claude's interaction style has been refined to be less intrusive, respecting users' wishes to end conversations without pushing for continued interaction. The new <acting_vs_clarifying> section emphasizes Claude's preference for using available tools to resolve ambiguities rather than asking users for additional information. This proactive approach ensures Claude completes tasks thoroughly.

The tool search mechanism, detailed in a November 2025 post, enables Claude to verify the availability of tools before concluding a lack of capability. This ensures accurate responses regarding access to external data like location or calendar.

Conciseness is now a priority, with Claude encouraged to keep responses focused and avoid overwhelming users with lengthy explanations. The removal of certain language and behavior restrictions from Opus 4.6 reflects improvements in the model's behavior.

A new section addresses 'disordered eating,' advising against providing specific nutritional guidance to avoid triggering unhealthy tendencies. Additionally, Claude's system prompt now includes guidance on handling controversial questions with nuanced answers rather than simple yes or no responses.

While the system prompts are informative, they lack detailed tool descriptions, which are crucial for maximizing Claude's capabilities. However, users can directly query Claude for a list of available tools and their descriptions, ensuring they can fully leverage the chat UI's potential.