In TFS 2005 running help from tf.exe popped up the MSDN help browser. That was a bit lame, but we didn't allocate the time to do it right. That's been fixed in TFS 2008.
Running tf.exe /? produces a list of commands, and tf someCommand /? produces detailed help on that command.
Here are a couple of examples. These two commands are also new in TFS 2008.
D:\>tf destroy /?TF - Team Foundation Version Control ToolCopyright (c) Microsoft Corporation. All rights reserved. Destroys, or permanently deletes, version-controlled items from TeamFoundation version control. tf destroy [/keephistory] itemspec1 [;versionspec] [itemspec2...itemspecN] [/stopat:versionspec] [/preview] [/startcleanup] [/noprompt] Versionspec: Date/Time Dmm/dd/yyyy or any .Net Framework-supported format or any of the date formats of the local machine Changeset number Cnnnnnn Label Llabelname Latest version T Workspace Wworkspacename;workspaceowner D:\>tf folderdiff /?TF - Team Foundation Version Control ToolCopyright (c) Microsoft Corporation. All rights reserved. Displays a visual representation of the differences between files in two serverfolders, in a server folder and a local folder, or in two local folders. tf folderdiff [sourcePath] targetPath [/recursive] [/noprompt] [/server:serverName:port] [/filter:filter] [/filterLocalPathsOnly] [/view:same,different,sourceOnly,targetOnly]
D:\>tf destroy /?TF - Team Foundation Version Control ToolCopyright (c) Microsoft Corporation. All rights reserved.
Destroys, or permanently deletes, version-controlled items from TeamFoundation version control.
tf destroy [/keephistory] itemspec1 [;versionspec] [itemspec2...itemspecN] [/stopat:versionspec] [/preview] [/startcleanup] [/noprompt]
Versionspec: Date/Time Dmm/dd/yyyy or any .Net Framework-supported format or any of the date formats of the local machine Changeset number Cnnnnnn Label Llabelname Latest version T Workspace Wworkspacename;workspaceowner
D:\>tf folderdiff /?TF - Team Foundation Version Control ToolCopyright (c) Microsoft Corporation. All rights reserved.
Displays a visual representation of the differences between files in two serverfolders, in a server folder and a local folder, or in two local folders.
tf folderdiff [sourcePath] targetPath [/recursive] [/noprompt] [/server:serverName:port] [/filter:filter] [/filterLocalPathsOnly] [/view:same,different,sourceOnly,targetOnly]