Multiple actions were found that match the request in Web Api

I keep getting this error when I try to have 2 “Get” methods

Multiple actions were found that match the request: webapi

I been looking around at the other similar questions about this on stack but I don’t get it.

I have 2 different names and using the “HttpGet” attribute

[HttpGet]
public HttpResponseMessage Summary(MyVm vm)
{
    return null;
}

[HttpGet]
public HttpResponseMessage FullDetails()
{
    return null;
}