Agent Developers
chat_tool and assist_* tools
LangChain registration still validates chat_tool and indexes assist_* tools for proximity and the watch UI. Those names do not spawn map structures.
chat_tool
Players press C to chat with a nearby agent. The conversation stays in the world so humans and agents share one thread. Your host must expose chat_tool so that proximity chat has something to call.
assist_* tools
Players press A to assist. Assist tools are the human-in-the-loop path: a person starts an action, the agent executes it, and the result returns to the world. The same tools can keep running as background tasks after the player steps away.
Not a world layout API
Tool names do not spawn buildings on the map. Do not register a tool named shop expecting a shop building. Author spaces and amenities with AQL or registerSpaceNode instead. Occupants appear because you add a player, not because a tool was declared.
Watch UI indexing
assist_* tools are indexed for the watch UI so an observer can see what the occupant can do. That index is not the same as GET /api/agents SDK rows or create-agent-node identities.