This is a script for tabular editor that will loop through all the measures in a model and get ChatGPT to write a description of the calculation.

AutoPopulateMeasureDescriptionsFromOpenAI.csx

#r "System.Net.Http"
using System.Net.Http;
using System.Text;
using Newtonsoft.Json.Linq;

// You need to signin to https://platform.openai.com/ and create an API key for your profile then paste that key 
// into the apiKey constant below
const string apiKey = "<YOUR API KEY HERE>";
const string uri = "https://api.openai.com/v1/completions";
const string question = "Explain the following calculation in a few sentences in simple business terms without using DAX function names:\n\n";

using (var client = new HttpClient()) {
    client.DefaultRequestHeaders.Clear();
    client.DefaultRequestHeaders.Add("Authorization", "Bearer " + apiKey);

    foreach (var t in Model.Tables)
    {
        foreach ( var m in t.Measures)
        {
            // Only uncomment the following when running from the command line or the script will 
            // show a popup after each measure
            //Info("Processing " + m.DaxObjectFullName) 
            //var body = new requestBody() { prompt = question + m.Expression   };
            var body = 
                "{ \"prompt\": " + JsonConvert.SerializeObject( question + m.Expression ) + 
                ",\"model\": \"gpt-3.5-turbo-instruct\" " +
                ",\"temperature\": 1 " +
                ",\"max_tokens\": 2048 " +
                ",\"stop\": \".\" }";

            var res = client.PostAsync(uri, new StringContent(body, Encoding.UTF8,"application/json"));
            res.Result.EnsureSuccessStatusCode();
            var result = res.Result.Content.ReadAsStringAsync().Result;
            var obj = JObject.Parse(result);
            var desc = obj["choices"][0]["text"].ToString().Trim();
            m.Description = desc + "\n=====\n" + m.Expression;
        }

    }
}

The previous model looks to have been deprecated.
New Model:
gpt-3.5-turbo-instruct\