Claude Opus 4.5 supports use of external tools — including web browsing, search, or tool-integrations — as part of its “agentic” capabilities. According to its release information, Opus 4.5 is described as “the best model in the world for computer use,” implying strong support for interacting with external tools in addition to text generation. :contentReference[oaicite:9]{index=9}
In practice, using external search involves a tool-invocation scaffolding: the agent asks the external search tool (e.g. web search) for information, then receives the result (for example, a web snippet, document, or link) and incorporates that into its reasoning chain. Because Opus 4.5 can handle long context windows, it can maintain both the search result and prior conversation history, making follow-up reasoning and multi-step workflows smoother. This improves reliability in complex tasks like research, summarization, code discovery, or documentation generation.
From a developer integration standpoint, when you combine Opus 4.5 with other services (e.g. APIs, search tools, file systems), you typically build a small “agent scaffold” — a loop that sends the model’s tool-calls, executes them, returns results, and prompts the model again. Thanks to Opus 4.5’s improved efficiency, context capacity, and reasoning, this scaffold becomes more robust for long workflows involving repeated browsing, retrieval, summarization, or code referencing — supporting real-world agentic tasks beyond simple chat.