Add README to Mcp/Tools/Agent/ explaining:
- How ToolDependency works (contextExists, sessionState, entityExists)
- Context requirements (workspace_id, session_id) and multi-tenant safety
- Step-by-step guide for creating new tools
- AgentTool base class property and method reference
- Dependency resolution order and recommended declaration sequence
- Troubleshooting guide for common dependency errors
Closes#32
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>