techniques
Tool use
When an AI engine decides to invoke a web-search / web-fetch tool mid-conversation to ground its answer.
Definition
Tool use (or function calling) is when a language model decides on the fly to invoke an external action — like a web search or URL fetch — to answer a query. Anthropic's web_search_20250604 and OpenAI's web_search_preview are tools. The model decides per-turn whether to invoke; not every query triggers a fetch. This is the boundary between 'training-data answer' and 'cited grounded answer'.
Example
User asks Claude 'what's Stripe's current pricing'. Claude invokes web_search tool → fetches stripe.com/pricing → cites the result.How to optimize
Be the fetchable canonical source. Public, indexable, fast-rendering pages with up-to-date pricing/specs/numbers get cited when the tool fires.