res <- list(
  tool_rnorm = ellmer::tool(
    fun = rnorm,
    description = "Draw numbers from a random normal distribution",
    arguments = list(
      n = ellmer::type_integer(
        "The number of observations. Must be a positive integer."
      ),
      mean = ellmer::type_number("The mean value of the distribution."),
      sd = ellmer::type_number(
        "The standard deviation of the distribution. Must be a non-negative number."
      )
    )
  )
)

res
