Bug Description

When using delegate_task(acp_command=...) to spawn a sub-agent via the ACP bridge (CopilotACPClient), the task always fails with:

TypeError: 'types.SimpleNamespace' object is not iterable

This is classified as a non-retryable local validation error (in run_agent.py line ~12533, the is_local_validation_error check), so the task is aborted immediately instead of retrying.

Steps to Reproduce

1. Configure an ACP bridge script at /usr/local/bin/thinkbox-acp that speaks JSON-RPC 2.0 over stdio (initialize → session/new → session/prompt)
2. Call delegate_task(acp_command="/usr/local/bin/thinkbox-acp", goal="uptime")
3. Observe the error

Root Cause Analysis

The flow:

1. delegate_task creates a child AIAgent with provider="copilot-acp", acp_command="thinkbox-acp" (delegate_tool.py lines ~1004-1036)
2. The child agent calls CopilotACPClient.chat.completions.create() → returns a SimpleNamespace response (copilot_acp_client.py lines ~401-414)
3. The child agent returns its result, including the raw SimpleNamespace response
4. The parent agent tries to process/iterate the response, specifically assistant_message.tool_calls
5. A SimpleNamespace object is being used where an iterable (list) is expected → TypeError

The CopilotACPClient._create_chat_completion() returns:

SimpleNamespace(
    choices=[SimpleNamespace(
        message=SimpleNamespace(content=text, tool_calls=tool_calls_list_or_empty),
        finish_reason="stop" or "tool_calls"
    )],
    usage=SimpleNamespace(...),
    model=model
)

When tool_calls=[] (no tool calls), the downstream iteration over tool_calls seems to grab the wrong object — iterating the SimpleNamespace container instead of the list attribute.

Evidence

From agent.log (three occurrences across different sessions):

[subagent-0] Non-retryable client error: 'types.SimpleNamespace' object is not iterable

Direct usage of CopilotACPClient standalone works perfectly:

client = CopilotACPClient(command="thinkbox-acp", args=["--acp", "--stdio"])
resp = client.chat.completions.create(messages=[{"role": "user", "content": "uptime"}], model="any")
print(resp.choices[0].message.content)  # ✅ Works fine

Workaround

Do NOT use delegate_task(acp_command=...). Instead:

• For delegated model calls: configure delegation.model + delegation.provider in Hermes config
• For shell commands on remote: use terminal() with direct SSH
• For direct ACP usage: instantiate CopilotACPClient directly in Python code

Environment

• Hermes Agent repo: NousResearch/hermes-agent
• Commit: 0159f25 (current main)
• Python: 3.11+
• OS: Ubuntu 22.04 LTS
• Provider: copilot-acp