Anthropic
Claude (with web tool)
Anthropic's frontier model with web_search_20250604 tool — values structural depth + provenance.
How it works
Claude (Anthropic's frontier model) gains web-retrieval capability when configured with the web_search_20250604 tool. Behavior: model decides per turn whether to fetch; if so, queries are dispatched to a retrieval system; results are read and synthesized into the response. Anthropic publishes that retrieval uses ensemble cosine + BM25 + authority + recency. Claude is known for being more conservative in its citations — preferring fewer but more authoritative sources, and explicitly avoiding hallucinated facts when retrieval coverage is sparse.
Official docsUser-agents
ClaudeBotClaude-Webanthropic-ai
Allow these in your robots.txt explicitly. Audit your current setup with the robots.txt analyzer.
Signals it weights heavily
- Structural depth (H2 hierarchy)
- Author bylines + credentials
- Outbound citations to primary sources
- JSON-LD presence
- Page content density
How to optimize for Claude (with web tool)
- Allow ClaudeBot + Claude-Web explicitly in robots.txt.
- Invest in structural depth — Claude rewards H2-segmented content over wall-of-text.
- Cite primary sources inline (Claude weights outbound-authority-links highly).
- Strong author E-E-A-T moves the needle more on Claude than ChatGPT.