tool_factory: Create a Tool

In aisdk: Unified Interface for AI Model Providers

Create a Tool

Description

Factory function to create a Tool object. This is the recommended way to define tools for LLM function calling.

Usage

tool(
  name,
  description,
  parameters = NULL,
  execute = NULL,
  layer = "llm",
  meta = NULL
)

Arguments

name	Unique tool name (used by LLM to call the tool).
description	Description of the tool's purpose. Be descriptive to help the LLM understand when to use this tool.
parameters	A z_schema object (z_object/z_any/etc), a named list, a character vector, or NULL. When NULL, the schema is inferred from the execute function signature (if possible) and defaults to flexible types.
execute	An R function that implements the tool logic. It can accept a single list argument (args), or standard named parameters. List-style functions receive a single list argument containing parameters.
layer	Tool layer: "llm" (loaded into context) or "computer" (executed via bash/filesystem). Default is "llm". Computer layer tools are not loaded into context but executed via bash.
meta	Optional metadata associated with the tool (e.g., list(cache_control = list(type = "ephemeral"))).

Value

A Tool object.

Examples

if (interactive()) {
  # Define a weather tool
  get_weather <- tool(
    name = "get_weather",
    description = "Get the current weather for a location",
    parameters = z_object(
      location = z_string(description = "The city name, e.g., 'Beijing'"),
      unit = z_enum(c("celsius", "fahrenheit"), description = "Temperature unit")
    ),
    execute = function(args) {
      # In real usage, call a weather API here
      paste("Weather in", args$location, "is 22 degrees", args$unit)
    }
  )

  # Use with generate_text
  result <- generate_text(
    model = "openai:gpt-4o",
    prompt = "What's the weather in Tokyo?",
    tools = list(get_weather)
  )
}

aisdk documentation built on May 29, 2026, 9:07 a.m.