ChatOptions.ToolMode doesn't enable require non-function tools

[stephentoub]

With ToolMode, you can specify that no tools should be used, any tools should be used, at least one tool should be used, or a specific tool must be used. But for the last one, it's limited only to function tools. With other kinds of tools becoming available, like web search, systems are starting to let you require that these tools be used, but there's no way to do that today via ToolMode.

[stephentoub]

One way I think might address this well would be to introduce a ToolMode-derived type that just wraps an AITool instance (or to augment the existing required mode type with the ability to be configured with an AITool. Then you could do things like:

options.Tools = [myAwesomeTool];
options.ToolMode = ChatToolMode.RequireSpecific(myAwesomeTool);