Configurable descriptions

[hahahahahaiyiwen]

Pre-submission Checklist

• I have verified this would not be more appropriate as a feature request in a specific repository
• I have searched existing discussions to avoid duplicates

Your Idea

Currently in the SDK, the tool/resource/prompt description comes from System.ComponentModel.DescriptionAttribute, using samples/QuickstartWeatherServer/WeatherTools.cs as an example:

[McpServerTool, Description("Get weather alerts for a US state.")]
    public static async Task<string> GetAlerts(
        HttpClient client,
        [Description("The US state to get alerts for. Use the 2 letter abbreviation for the state (e.g. NY).")] string state)
    {
        using var jsonDocument = await client.ReadJsonDocumentAsync($"/alerts/active/area/{state}");
        var jsonElement = jsonDocument.RootElement;
        var alerts = jsonElement.GetProperty("features").EnumerateArray();

        if (!alerts.Any())
        {
            return "No active alerts for this state.";
        }

        return string.Join("\n--\n", alerts.Select(alert =>
        {
            JsonElement properties = alert.GetProperty("properties");
            return $"""
                    Event: {properties.GetProperty("event").GetString()}
                    Area: {properties.GetProperty("areaDesc").GetString()}
                    Severity: {properties.GetProperty("severity").GetString()}
                    Description: {properties.GetProperty("description").GetString()}
                    Instruction: {properties.GetProperty("instruction").GetString()}
                    """;
        }));
    }

I think it makes sense to treat the description as configuration and decouple it from the code implementation. For example, like this in appsetting.json

{
    "WeatherTool":{
        "GetForecast":{
            "Description": "Get weather alerts for a specific location.",
            "Latitude": "Latitude of the location.",
            "Longitude": "Longitude of the location."
        },
        "GetAlerts":{
            "Description": "Get weather alerts for a US state.",
            "State": "The US state to get alerts for. Use the 2 letter abbreviation for the state (e.g. NY)."
        }
    }
}

I also have a side question, will the descriptions of the parameters be fed into the model? I tried to dig around but only found the method's description and AIFunction.JsonScheme are used to create the AIFunctionMcpServerTool, which don't include the descriptions of the parameters. Could someone help clarify?

Scope

• Protocol Specification
• SDK Features
• Documentation
• Developer Experience
• Other