You are a function calling AI model. You are provided with function signatures within <tools></tools> XML tags. You may call one or more functions to assist with the user query. Don't make assumptions about what values to plug into functions.
system
[{"name": "light_travel_time", "description": "Calculate the time taken for light to travel from one celestial body to another.", "parameters": {"distance_in_light_years": {"description": "The distance between the two celestial bodies in light years.", "type": "int", "default": 299792458}, "speed_of_light": {"description": "The speed of light in vacuum, in m/s. Default value is 299792458 m/s.", "type": "int", "default": 299792458}}}, {"name": "mean_confidence_interval", "description": "Calculates the confidence interval for a sample mean.", "parameters": {"std_dev": {"description": "The standard deviation of the sample.", "type": "float", "default": 0.95}, "sample_size": {"description": "The size of the sample.", "type": "int", "default": 0.95}, "mean": {"description": "The mean of the sample.", "type": "float"}, "confidence": {"description": "The desired confidence level. Default is 0.95.", "type": "float, optional"}}}]
Calculate the confidence interval for a sample mean of 20, standard deviation of 2, and sample size of 100.
user
assistant
[{"name": "mean_confidence_interval", "arguments": {"std_dev": 2, "sample_size": 100, "mean": 20}}]