I've been tinkering with building something similar for myself - though for a generic chatbot, rather than for Claude (not every task is coding, and I'd like to keep !). From other comments (e.g. https://news.ycombinator.com/item?id=46428368, https://news.ycombinator.com/item?id=46427950) suggest that many others are already ahead of me. Any recs for tools, libraries, or approaches that I should learn from or adopt? In particular, I've found that - no matter how direct and clear the system prompt is - models have a tendency to respond verbally as if they've made a tool-call recording some gained-knowledge ("thanks! I'll remember that"), but to not actually return the JSON required to trigger the call by the tool.