Use a single parameter to represent the tool request object

[anthony-c-martin]

Pre-submission Checklist

• I have checked that this question would not be more appropriate as an issue in a specific repository
• I have searched existing discussions and documentation for answers

Question Category

• Protocol Specification
• SDK Usage
• Server Implementation
• General Implementation
• Documentation
• Other

Your Question

I currently have code that looks like the following:

[McpServerToolType]
public static class MyTools
{
    [McpServerTool, Description("Tool description ...")]
    public static async Task<string> ToolMethod1(
        [Description("Parameter 1 description ...")]
        string parameter1,
        [Description("Parameter 2 description ...")]
        string parameter2,
        [Description("Parameter 3 description ... Optional.")]
        List<MyParamType>? parameter3Optional = null)
    {
        // Some processing ...
    }
}

What I'd really like to be able to write is something like the following, where "request" represents the full payload body schema, rather than a parameter named "request", which would be the default behavior:

[McpServerToolType]
public static class MyTools
{
    [McpServerTool, Description("Tool description ...")]
    public static async Task<string> ToolMethod1(ToolMethod1Request request)
    {
        // Some processing ...
    }
}

public class ToolMethod1Request
{
    [Description("Parameter 1 description ...")]
    public required string parameter1 { get; set; }

    [Description("Parameter 2 description ...")]
    public required string parameter2 { get; set; }

    [Description("Parameter 3 description ... Optional.")]
    public List<MyParamType>? parameter3Optional { get; set; }
}

The benefit of this approach is that the code declaring the schema the "top-level" request can be authored similarly to the code for types in nested properties.

Is this something that's possible today?