Strengthen tool preprompt to reduce unnecessary tool calls
Restructure the system prompt in buildToolPreprompt to more aggressively
discourage models from calling tools when they can answer directly.
- Lead with a prominent "Do NOT use tools" block listing concrete
examples of tasks that should never trigger tool calls (coding,
creative writing, math, general knowledge, building apps)
- Switch from single space-joined paragraph to newline-separated
sections so models can parse distinct directives more reliably
- Clarify the threshold: only call tools when the request REQUIRES
external data the model does not have
- Consolidate image instructions under a single IMAGES heading
https://claude.ai/code/session_0151FUrN7XkXeS4FNhB9mz4C
