该错误消息非常清楚，您的存储过程在从 C# 代码传递参数时不需要任何参数.

The error message is pretty clear that your stored procedure does not expects any parameter while from c# code you are passing parameter.

实际上，您在存储过程中指定了一个变量而不是参数，您需要在 SP 名称参数之后使用它的数据类型指定它，在您的情况下，OUTPUT 关键字作为它的输出参数.

Actually you have specified a variable in your stored procedure not a parameter, you will need to specify it just after the SP name parameter with it's datatype and in your case OUTPUT keyword as it output parameter.

应该是:

ALTER procedure [dbo].[spCaller] @URL NVarChar(255) OUTPUT
.......
.......

您的最终存储过程将类似于:

Your final stored procedure would be like:

ALTER procedure [dbo].[spCaller] @URL NVarChar(255) OUTPUT
AS BEGIN
EXECUTE spBuscarUrl  
    'MIREX-2017-00001', @url = @URL OUTPUT;  
select @URL
END

你可以看看这篇文章 解释了如何将不同类型的参数传递给存储过程.

You can have a look at this post explaining how to pass different kind of parameters to a Stored Procedure.

希望有帮助！