Web search and URL fetching via Perplexity (default: sonar, optional: sonar-pro). Use when searching the web, looking up information, fetching URL content, or configuring web search settings. Covers web_search tool (Perplexity direct API) and web_fetch tool (HTML to markdown extraction).

通过Perplexity进行网页搜索和URL获取（默认：sonar，可选：sonar-pro）。用于网页搜索、信息查询、获取URL内容或配置网页搜索设置。涵盖web_search工具（Perplexity直接API）和web_fetch工具（HTML转Markdown提取）