Fix how Tools are stored.

[andreibondarev]

Currently when using the langchainrb_rails:assistant generator, we just store the class names of tools: https://github.com/patterns-ai-core/langchainrb_rails/blob/main/lib/langchainrb_overrides/assistant.rb#L27. This is problematic as tools are oftentimes instantiated with various environment variables. Should we store the initialization info as well?

[mattlindsey]

Seems like this will be a little complicated since you need to create an instance of each tool (e.g., MovieInfoTool.new(api_key: "...") here:

langchainrb_rails/lib/langchainrb_overrides/assistant.rb

Line 56 in dfad638

assistant = Langchain::Assistant.new(

For now you could just add code there to create any of the 8 'official' tools whose class names are stored and whose 'required environment variables' (in the README) are defined properly.

P.S.
Actually it looks like if you just fix the Google and Weather tools to have defaults in their initalize like NewsRetriever below, you should be all set just doing ToolName.new on each.

    def initialize(api_key: ENV["NEWS_API_KEY"])
      @api_key = api_key
    end

[emk-klaay]

I created an ApplicationTool in my application, and all tools inherit from it. It has a unified initialization signature. This allows a strong convention for retrieving API keys and other information from the environment. This allows us to store the tools as an array ([langchain/tool/name, ...]) on the assistant.