Yield content alongside tool calls

[JosephMarinier]

I recommend reviewing the commits one by one:

• This doesn't change anything; it just makes the diff of the following commit clearer.
  • Flip the if/else
  • Unindent by removing the else after the return
• Strip content before checking if it is truthy
• Yield content alongside tool calls

[gabegma]

Looks great!! Thank you for testing this!