Fixing an issue where MCP server wuld still hang on studio instead of asking for firebase login (#8903)

Author: joehan

src/mcp/errors.ts

@@ -6,8 +6,14 @@ export const NO_PROJECT_ERROR = mcpError(
   "PRECONDITION_FAILED",
 );
 
-export function mcpAuthError(): CallToolResult {
+export function mcpAuthError(skipADC: boolean): CallToolResult {
   const cmd = commandExistsSync("firebase") ? "firebase" : "npx -y firebase-tools";
+  if (skipADC) {
+    return mcpError(`The user is not currently logged into the Firebase CLI, which is required to use this tool. Please instruct the user to execute this shell command to sign in.
+\`\`\`sh
+${cmd} login
+\`\`\``);
+  }
   return mcpError(`The user is not currently logged into the Firebase CLI, which is required to use this tool. Please instruct the user to execute this shell command to sign in or to configure [Application Default Credentials][ADC] on their machine.
 \`\`\`sh
 ${cmd} login

src/mcp/index.ts

@@ -283,9 +283,10 @@ export class FirebaseMcpServer {
     projectId = projectId || "";
 
     // Check if the user is logged in.
-    const accountEmail = await this.getAuthenticatedUser();
+    const skipAutoAuthForStudio = isFirebaseStudio();
+    const accountEmail = await this.getAuthenticatedUser(skipAutoAuthForStudio);
     if (tool.mcp._meta?.requiresAuth && !accountEmail) {
-      return mcpAuthError();
+      return mcpAuthError(skipAutoAuthForStudio);
     }
 
     // Check if the tool requires Gemini in Firebase API.