{
  "id": "web-search-tool",
  "code": "PTL-0137",
  "term": "Web Search Tool",
  "aliases": [
    "web browsing",
    "search grounding",
    "grounding with search",
    "browsing tool"
  ],
  "category": "retrieval-tools",
  "definition": "A web search tool lets a language model issue search queries, read the results, and ground its answer in current web content, usually returning citations to the pages it used.",
  "description": "Search is the main remedy for a model's knowledge cutoff and for questions about prices, news, and other changing facts. Early work trained a model to browse with a text-based browser and cite its sources. Today providers offer search as a built-in tool. Search results are untrusted input, so they are a vector for indirect prompt injection.",
  "example": null,
  "broader": [
    "function-calling"
  ],
  "narrower": [],
  "related": [
    "knowledge-cutoff",
    "citation-generation",
    "retrieval-augmented-generation",
    "indirect-prompt-injection"
  ],
  "introduced": 2021,
  "added": "2026-10-10",
  "sources": [
    {
      "title": "WebGPT: Browser-assisted question-answering with human feedback",
      "authors": "Nakano et al.",
      "year": 2021,
      "url": "https://arxiv.org/abs/2112.09332"
    },
    {
      "title": "Web search tool",
      "authors": "Anthropic",
      "year": 2025,
      "url": "https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool"
    }
  ],
  "url": "https://protologue.com/t/web-search-tool/",
  "citation": "Protologue. (2026). Web Search Tool. In Protologue: A Taxonomy of Prompting and LLM Techniques (v1.4.0, PTL-0137). https://protologue.com/t/web-search-tool/"
}