Create tooltips using Attributes

I would say ideally you write your own extension to generate <input> . The original source can help . See this method:

private static MvcHtmlString InputHelper(HtmlHelper htmlHelper, InputType inputType, ModelMetadata metadata, string name, object value, bool useViewData, bool isChecked, bool setId, bool isExplicitValue, string format, IDictionary<string, object> htmlAttributes)
    { ... }

Here you could use:

@Html.TextBoxWthTooltipFor(model => model.Nome, ...)

I ended up going the other way. I realized that I could put the tooltip in a span tag instead of putting it in the element itself.

It looks like this:

public static MvcToolTip ToolTipFor<TModel, TValue> (this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TValue>> expression,  string placement = "right")
{
    var exp = (MemberExpression) expression.Body;
    var attributes = exp.Expression.Type.GetProperty(exp.Member.Name).GetCustomAttributes(typeof(ToolTipAttribute), false);

    var message = (((ToolTipAttribute) attributes[0]).Description);

    return new MvcToolTip(htmlHelper.ViewContext, message, placement);
}

public class MvcToolTip : IDisposable
{
    private readonly TextWriter _writer;

    public MvcToolTip(ViewContext viewContext, string message, string placement = "right")
    {
        _writer = viewContext.Writer;

        _writer.Write("<span data-toggle='tooltip' data-original-title='" + message + "' data-placement='" + placement + "'>");

    }

    public void Dispose()
    {
        _writer.Write("</span>");
    }
}

Usage:

@using (Html.ToolTipFor(m => m.Pessoa.Nome))
{
    @Html.TextBoxFor(m => m.Pessoa.Nome, new {@class = "form-control"})
}
<script> $("[data-toggle='tooltip']").tooltip(); </script>