diff --git a/packages/cli/src/utils/sandbox-macos-minimal.sb b/packages/cli/src/utils/sandbox-macos-minimal.sb
index 5a8b46dd..4b96fa3d 100644
--- a/packages/cli/src/utils/sandbox-macos-minimal.sb
+++ b/packages/cli/src/utils/sandbox-macos-minimal.sb
@@ -10,6 +10,7 @@
     (subpath (param "TMP_DIR"))
     (subpath (string-append (param "HOME_DIR") "/.gemini"))
     (subpath (string-append (param "HOME_DIR") "/.npm"))
+    (subpath (string-append (param "HOME_DIR") "/.cache"))
     (literal "/dev/stdout")
     (literal "/dev/stderr")
     (literal "/dev/null")
diff --git a/packages/cli/src/utils/sandbox-macos-strict.sb b/packages/cli/src/utils/sandbox-macos-strict.sb
index 1a7c63d0..cd53fa61 100644
--- a/packages/cli/src/utils/sandbox-macos-strict.sb
+++ b/packages/cli/src/utils/sandbox-macos-strict.sb
@@ -68,6 +68,7 @@
     (subpath (param "TMP_DIR"))
     (subpath (string-append (param "HOME_DIR") "/.gemini"))
     (subpath (string-append (param "HOME_DIR") "/.npm"))
+    (subpath (string-append (param "HOME_DIR") "/.cache"))
     (literal "/dev/stdout")
     (literal "/dev/stderr")
     (literal "/dev/null")
diff --git a/packages/server/src/tools/tool-registry.ts b/packages/server/src/tools/tool-registry.ts
index d7aaa5f6..f62a3256 100644
--- a/packages/server/src/tools/tool-registry.ts
+++ b/packages/server/src/tools/tool-registry.ts
@@ -187,7 +187,15 @@ export class ToolRegistry {
             command: mcpServerCmd,
             stderr: 'pipe',
           });
-          await this.mcpClient.connect(transport);
+          try {
+            await this.mcpClient.connect(transport);
+          } catch (error) {
+            console.error(
+              'failed to start or connect to MCP server using ' +
+                `command '${mcpServerCmd}'; \n${error}`,
+            );
+            throw error;
+          }
           this.mcpClient.onerror = (error) => {
             console.error('MCP ERROR', error.toString());
           };