from agent_trace import tracer, record_decision

async def run_agent_step(goal: str, context: dict) -> dict:
    # Open a new trace span for this decision cycle
    with tracer.start_span("agent.step", attrs={
        "goal":    goal,
        "ctx_keys": list(context.keys()),
    }) as span:

        # 1. Tool selection
        with span.child("tool.select"):
            tool, score = await select_tool(goal, context)
            record_decision(tool=tool, confidence=score)

        # 2. Execution
        with span.child("tool.exec", attrs={"tool": tool.name}):
            result = await tool.run(context)
            span.set_attr("result_tokens", result.token_count)

        # 3. Reasoning synthesis
        with span.child("reason.synth"):
            answer = await synthesise(goal, result)
            span.set_attr("answer_score", answer.score)

        return {"answer": answer, "trace_id": span.trace_id}