Fix mcp list-tools tab completion offering completions for second positional arg

pkg/cli/mcp_list_tools.go

@@ -203,7 +203,12 @@ The command will:
 
 			return ListToolsForMCP(workflowFile, serverFilter, verbose)
 		},
-		ValidArgsFunction: CompleteWorkflowNames,
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) > 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			return CompleteWorkflowNames(cmd, args, toComplete)
+		},
 	}
 
 	cmd.Flags().StringVar(&serverFilter, "server", "", "MCP server name to list tools for")

pkg/cli/mcp_list_tools_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/github/gh-aw/pkg/constants"
 	"github.com/github/gh-aw/pkg/parser"
 	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/spf13/cobra"
 )
 
 func TestListToolsForMCP(t *testing.T) {
@@ -336,3 +337,43 @@ func TestNewMCPListToolsSubcommand(t *testing.T) {
 		t.Error("Expected 'server' flag to be marked as required")
 	}
 }
+
+func TestMCPListToolsValidArgsFunction(t *testing.T) {
+	cmd := NewMCPListToolsSubcommand()
+
+	t.Run("no_completions_when_first_arg_already_provided", func(t *testing.T) {
+		completions, directive := cmd.ValidArgsFunction(cmd, []string{"my-workflow"}, "")
+		if len(completions) != 0 {
+			t.Errorf("Expected no completions when first arg is already provided, got: %v", completions)
+		}
+		if directive != cobra.ShellCompDirectiveNoFileComp {
+			t.Errorf("Expected ShellCompDirectiveNoFileComp, got: %v", directive)
+		}
+	})
+
+	t.Run("completions_offered_for_first_arg", func(t *testing.T) {
+		// Set up a temporary workflow directory so CompleteWorkflowNames finds files.
+		tmpDir := testutil.TempDir(t, "test-*")
+		workflowsDir := filepath.Join(tmpDir, constants.GetWorkflowDir())
+		if err := os.MkdirAll(workflowsDir, 0755); err != nil {
+			t.Fatalf("Failed to create workflows dir: %v", err)
+		}
+		content := "---\nengine: copilot\n---\n# Workflow\n"
+		if err := os.WriteFile(filepath.Join(workflowsDir, "my-workflow.md"), []byte(content), 0644); err != nil {
+			t.Fatalf("Failed to write workflow file: %v", err)
+		}
+		origDir, err := os.Getwd()
+		if err != nil {
+			t.Fatalf("Failed to get current directory: %v", err)
+		}
+		defer os.Chdir(origDir)
+		if err := os.Chdir(tmpDir); err != nil {
+			t.Fatalf("Failed to change to temp directory: %v", err)
+		}
+
+		completions, _ := cmd.ValidArgsFunction(cmd, []string{}, "")
+		if len(completions) == 0 {
+			t.Error("Expected at least one completion for first positional arg when workflows exist")
+		}
+	})
+}