Function tool_loop 

pub async fn tool_loop<Ctx: LoopDepth + Send + Sync + 'static>(
    provider: &dyn DynProvider,
    registry: &ToolRegistry<Ctx>,
    params: ChatParams,
    config: ToolLoopConfig,
    ctx: &Ctx,
) -> Result<ToolLoopResult, LlmError>

Runs the LLM in a tool-calling loop until completion.

Each iteration:

1. Calls provider.generate_boxed() with the current messages
2. If the response contains tool calls, executes them via the registry
3. Appends tool results as messages and repeats
4. Stops when the LLM returns without tool calls, or max iterations is reached

Depth Tracking

If Ctx implements LoopDepth, nested calls are tracked automatically. When config.max_depth is set and the context’s depth exceeds the limit, returns Err(LlmError::MaxDepthExceeded).

Events

If config.on_event is set, the callback will be invoked with ToolLoopEvents at key points during execution:

• ToolLoopEvent::IterationStart at the beginning of each iteration
• ToolLoopEvent::LlmResponseReceived after the LLM responds
• ToolLoopEvent::ToolExecutionStart before each tool executes
• ToolLoopEvent::ToolExecutionEnd after each tool completes

Errors

Returns LlmError if:

• The provider returns an error
• Max depth is exceeded (returns LlmError::MaxDepthExceeded)
• Max iterations is exceeded (returns in result with TerminationReason::MaxIterations)