Multiple tools with self-ask-with-search

[nkov]

The self-ask-with-search agent allows the LLM to use "intermediate" searches to obtain an answer to a query.

Example from prompt template:

Question: Who lived longer, Muhammad Ali or Alan Turing?
Are follow up questions needed here: Yes.
Follow up: How old was Muhammad Ali when he died?
Intermediate answer: Muhammad Ali was 74 years old when he died.
Follow up: How old was Alan Turing when he died?
Intermediate answer: Alan Turing was 41 years old when he died.
So the final answer is: Muhammad Ali

This is really powerful and in my experience, produces better results than the chat-conversational-react-description agent for searching, barring some minor technical issues. However, it only has the ability to use a single tool: Intermediate Answer.

I'm curious to understand the reasoning for this limitation, is this just missing implementation for using multiple tools, or is there a fundamental reason this type of agent can only use one tool?