When a model emits tool invocations as plain assistant text instead of
using the function-calling API (e.g. "execute_code: steps=[...]"), the
loop now returns ToolUnsupportedError. This lets freeloader blacklist the
model and cycle to one that properly supports function calling.
Detection: after a turn with stopReason="stop" and no API-level tool
calls, scan assistant text for any registered tool name followed by ':'
or '('. Only fires when tools are configured.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Levi Neely