tool: Define a tool

In ellmer: Chat with Large Language Models

Define a tool

Description

Define an R function for use by a chatbot. The function will always be run in the current R instance.

Learn more in vignette("tool-calling").

Usage

tool(.fun, .description, ..., .name = NULL)

Arguments

.fun	The function to be invoked when the tool is called.
.description	A detailed description of what the function does. Generally, the more information that you can provide here, the better.
...	Name-type pairs that define the arguments accepted by the function. Each element should be created by a type_*() function.
.name	The name of the function.

Value

An S7 ToolDef object.

Examples

# First define the metadata that the model uses to figure out when to
# call the tool
tool_rnorm <- tool(
  rnorm,
  "Drawn numbers from a random normal distribution",
  n = type_integer("The number of observations. Must be a positive integer."),
  mean = type_number("The mean value of the distribution."),
  sd = type_number("The standard deviation of the distribution. Must be a non-negative number.")
)
chat <- chat_openai()
# Then register it
chat$register_tool(tool_rnorm)

# Then ask a question that needs it.
chat$chat("
  Give me five numbers from a random normal distribution.
")

# Look at the chat history to see how tool calling works:
# Assistant sends a tool request which is evaluated locally and
# results are send back in a tool result.

ellmer documentation built on April 4, 2025, 3:53 a.m.