This commit addresses PR feedback regarding the prefixing of isolated subagent MCP servers and its potential to break existing security policies relying on standard FQNs.
1. Added `originalName` to `MCPServerConfig` and `originalServerName` to `DiscoveredMCPTool`.
2. Updated `CoreToolScheduler` to reconstruct the original FQN (without the `__agent__` prefix) when performing policy checks via the Policy Engine. This ensures policies mapping to standard `mcp_{server}_{tool}` formats still apply correctly to isolated agents.
3. Added a remote agent back to `NewAgentsNotification.test.tsx` to maintain coverage for both local and remote agents.
Unit tests added:
1. Tool Registry Filtering: Verified that main registry hides all '__agent__' prefixed tools.
2. Subagent Tool Inheritance: Verified that agents correctly filter out other agents' MCP tools while retaining their own.
Verified with vitest in packages/core.
I've tactically refactored the `LocalAgentExecutor` so that it avoids shutting down and restarting subagent MCP servers for every agent execution, which mitigates the performance overhead caused by long startup times.
1. Leveraging the Global McpClientManager:
Instead of instantiating an entirely new `McpClientManager` instance within the `LocalAgentExecutor` per execution (and shutting it down in its `finally` block), we now use the single global `McpClientManager` available on `context.config`. Since the global manager deduplicates connection attempts by checking if the server is already active, subagent MCP servers will now naturally stay alive after their initial initialization.
2. Prefixing to Avoid Polluting the Global Namespace:
To isolate the agent-specific tools, we now register the subagent's MCP servers with a unique prefix: `__agent__${definition.name}__${name}`.
3. Strict Filtering for True Isolation (ToolRegistry):
- Main CLI context: Added a block in the global `ToolRegistry.getFunctionDeclarations()` that strictly hides any tool belonging to a server prefixed with `__agent__` if the registry `isMainRegistry`. This prevents internal subagent tools from leaking to the main agent.
- Subagent context (`LocalAgentExecutor`): When inheriting tools from the parent registry (the fallback when an agent doesn't explicitly define `tools: []`), the agent now ignores `__agent__` prefixed tools that belong to *other* agents, ensuring strict tool isolation while keeping the actual underlying server processes alive and reusable.
Akhilesh Kumar