Graph RAG-Tool Fusion
This addresses the limitation in tool retrieval for LLM agents scaling to hundreds or thousands of tools, improving accuracy in capturing tool dependencies, though it is incremental as it builds on existing RAG methods.
The paper tackles the problem of traditional RAG-based tool retrieval failing to capture structured dependencies between tools, such as APIs requiring parameters from other tools, by introducing Graph RAG-Tool Fusion, which combines vector-based retrieval with graph traversal to improve retrieval accuracy, achieving absolute improvements of 71.7% and 22.1% over naïve RAG on benchmarks.
Recent developments in retrieval-augmented generation (RAG) for selecting relevant tools from a tool knowledge base enable LLM agents to scale their complex tool calling capabilities to hundreds or thousands of external tools, APIs, or agents-as-tools. However, traditional RAG-based tool retrieval fails to capture structured dependencies between tools, limiting the retrieval accuracy of a retrieved tool's dependencies. For example, among a vector database of tools, a "get stock price" API requires a "stock ticker" parameter from a "get stock ticker" API, and both depend on OS-level internet connectivity tools. In this paper, we address this limitation by introducing Graph RAG-Tool Fusion, a novel plug-and-play approach that combines the strengths of vector-based retrieval with efficient graph traversal to capture all relevant tools (nodes) along with any nested dependencies (edges) within the predefined tool knowledge graph. We also present ToolLinkOS, a new tool selection benchmark of 573 fictional tools, spanning over 15 industries, each with an average of 6.3 tool dependencies. We demonstrate that Graph RAG-Tool Fusion achieves absolute improvements of 71.7% and 22.1% over naïve RAG on ToolLinkOS and ToolSandbox benchmarks, respectively (mAP@10). ToolLinkOS dataset is available at https://github.com/EliasLumer/Graph-RAG-Tool-Fusion-ToolLinkOS