From 7ff6f40ed020a12b8f496ced6934fd05759baf07 Mon Sep 17 00:00:00 2001
From: Sehoon Shon <sshon@google.com>
Date: Mon, 23 Mar 2026 19:14:54 -0400
Subject: [PATCH] Revert "perf(core): parallelize tool discovery"

---
 packages/core/src/config/config.ts | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index 5e9f6af653..e52a286e7a 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -1288,27 +1288,18 @@ export class Config implements McpContext, AgentLoopContext {
     // Initialize centralized FileDiscoveryService
     const discoverToolsHandle = startupProfiler.start('discover_tools');
     this.getFileService();
-
-    const discoveryPromises: Array<Promise<unknown>> = [];
-
     if (this.getCheckpointingEnabled()) {
-      discoveryPromises.push(this.getGitService());
+      await this.getGitService();
     }
-
     this._promptRegistry = new PromptRegistry();
     this._resourceRegistry = new ResourceRegistry();
 
     this.agentRegistry = new AgentRegistry(this);
-    discoveryPromises.push(this.agentRegistry.initialize());
+    await this.agentRegistry.initialize();
 
     coreEvents.on(CoreEvent.AgentsRefreshed, this.onAgentsRefreshed);
 
-    const toolRegistryPromise = this.createToolRegistry().then((registry) => {
-      this._toolRegistry = registry;
-    });
-    discoveryPromises.push(toolRegistryPromise);
-
-    await Promise.all(discoveryPromises);
+    this._toolRegistry = await this.createToolRegistry();
     discoverToolsHandle?.end();
     this.mcpClientManager = new McpClientManager(
       this.clientVersion,