FrontierAI.Engineer
Tool Use & Function Calling

Tool Router

A tool router is the logic — implemented in prompt, code, or a dedicated model — that selects which tool to invoke given the current state of the agent's task. Simple routers let the model choose freely from all available tools; more sophisticated routers filter the candidate set based on task context or enforce policies about which tools are permitted in a given situation, reducing the chance of irrelevant or unsafe tool selection.