https://msdn.microsoft.com/zh-cn/library/aa347733.aspx
参数：
/directory:<directory>
Directory to create files in. Default: The current directory.
Short form: /d 缩写
How to: Use Svcutil.exe to Download Metadata Documents
Locate the Svcutil.exe tool at the following location:
C:\Program Files\Microsoft SDKs\Windows\v1.0. \bin
At the command prompt, launch the tool using the following format.
svcutil.exe /t:metadata <url>* | <epr>
You must specify the /t:metadata option to download metadata. Otherwise, client code and configuration are generated.
The <url> argument specifies the URL to a service endpoint that provides metadata or to a metadata document hosted online. The <epr> argument specifies the path to an XML file that contains a WS-Addressing EndpointAddress for a service endpoint that supports WS-MetadataExchange.
ServiceModel Metadata Utility Tool (Svcutil.exe)
原文：http://www.cnblogs.com/chucklu/p/4650287.html