System Prompt Changes Between Claude Opus 4.6 and 4.7

Based on Anthropic's public Claude.ai system prompt, the differences between Opus 4.6 and 4.7 were compared.

The key changes are as follows.

• The name of the developer platform was changed to Claude Platform, and Claude in Chrome, Claude in Excel, and Claude in Powerpoint were added to the tool list.
• An acting_vs_clarifying instruction was added, telling Claude to make a reasonable attempt first rather than asking follow-up questions when minor information is missing from a user's request.
• There are signs that tool_search has been introduced, and it is now explicitly stated that Claude should first check whether an available tool exists before saying it cannot access something.
• An instruction was added to keep responses shorter and more focused.
• Language was added stating that if a user says they want to end the conversation, Claude should respect the request to stop rather than trying to prompt further interaction.

Safety instructions were also strengthened.

• A new critical_child_safety_instructions tag was added, and the child safety section was greatly expanded.
• Guidance on disordered eating was added, specifying that if related signs appear, Claude should not provide precise nutrition, diet, or exercise instructions with specific numbers, targets, or step-by-step plans.
• On complex or controversial issues, if forced into a yes/no style answer, Claude should refuse that format and give a nuanced answer instead.

Some phrases were also removed.

• The instruction in 4.6 to avoid emotes/action expressions, as well as the guidance to avoid words like "genuinely," "honestly," and "straightforward," were deleted.
• The explicit calibration language regarding Donald Trump that was present in 4.6 is also absent in 4.7.

It is also emphasized that the public prompt alone is not sufficient, and that the tool descriptions provided to the model are important for understanding actual behavior. When Claude was directly asked to list its tools and descriptions, several tools were confirmed, including ask_user_input_v0, bash_tool, conversation_search, web_search, and tool_search, but this list itself does not appear to have changed significantly since 4.6.