Transform subAgent tool into agentStart and agentMessage tools

Problem Statement

Currently, the subAgent tool creates a sub-agent that runs autonomously until completion. This can lead to sub-agents getting off task and wasting time, as there's no way for the parent agent to monitor or intervene in the sub-agent's execution.

Proposed Solution

Transform the subAgent tool into two separate tools similar to how shellStart and shellMessage work:

1. agentStart: Starts a sub-agent and immediately returns an instance ID

   • Does not wait for any timeout before returning (unlike shellStart)
   • Returns immediately so the parent agent can continue execution

2. agentMessage: Bidirectional communication with a running sub-agent

   • Get the current state/output of the sub-agent
   • Send instructions or guidance to the sub-agent
   • Optionally terminate the sub-agent

Benefits

• Parent agents can monitor sub-agent progress in real-time
• Parent agents can provide guidance or correction if sub-agents get off track
• Multiple sub-agents can run in parallel with parent supervision
• Improved efficiency by preventing sub-agents from wasting time on unproductive paths

Requirements

agentStart Tool

• Similar parameters to the current subAgent tool
• Returns an instance ID and initial state immediately
• Maintains a global map of running sub-agents (similar to processStates in shellStart)
• Sub-agent execution happens asynchronously

agentMessage Tool

• Takes an instance ID parameter to identify which sub-agent to interact with
• Allows getting the current state/output of the sub-agent
• Optionally allows sending guidance or instructions to the sub-agent
• Optionally allows terminating the sub-agent

Implementation Notes

• Keep the existing subAgent tool for backward compatibility and comparison
• Create a new implementation that uses the same toolAgent core but in an asynchronous manner
• Ensure proper cleanup of resources when sub-agents complete or are terminated

Acceptance Criteria

• New agentStart and agentMessage tools implemented
• Existing subAgent tool maintained for backward compatibility
• Documentation updated to explain both approaches
• Tests added for the new tools
• Example usage provided in documentation