The API request notably includes the exact text it cites from its sources (https://docs.anthropic.com/en/docs/build-with-claude/tool-us...), which is nifty.
Cost-wise it's interesting. $10/1000 queries is much cheaper for heavy use than Google's Gemini (1500 free per day then $35/1000) when you'd expect Google to be the cheaper option. https://ai.google.dev/gemini-api/docs/grounding