This thing has the "the natural language nailed" to the same degree that a BERT has. That's a far cry from the intelligence level required to output text of any sensible length, and even farther from the structural adherence required for tool calls.
Highly-structured outputs (like what you'd need for tool calls) seems like it'd be easier to put out than arbitrary text, no? At the very least, even something like BERT could make the decision of “Would any of my available tools be useful here?” and delegate to some deeper-thinking model to structure that tool call.