fix(adk): read resource-type MCP content in extractFunctionResponseContent

go/adk/pkg/models/base.go

@@ -150,9 +150,23 @@ func extractFunctionResponseContent(resp any) string {
 		if c, ok := m["content"].([]any); ok && len(c) > 0 {
 			var parts []string
 			for _, item := range c {
-				if itemMap, ok := item.(map[string]any); ok {
-					if t, ok := itemMap["text"].(string); ok {
-						parts = append(parts, t)
+				itemMap, ok := item.(map[string]any)
+				if !ok {
+					continue
+				}
+				if t, ok := itemMap["text"].(string); ok {
+					parts = append(parts, t)
+					continue
+				}
+				// "resource" content (e.g. GitHub MCP's get_file_contents) carries
+				// its payload nested under resource.text rather than a top-level
+				// text key; without this the caller only ever sees the sibling
+				// placeholder text item.
+				if itemMap["type"] == "resource" {
+					if resource, ok := itemMap["resource"].(map[string]any); ok {
+						if t, ok := resource["text"].(string); ok {
+							parts = append(parts, t)
+						}
 					}
 				}
 			}

go/adk/pkg/models/base_test.go

@@ -64,3 +64,52 @@ func TestMergeSystemInstructionFromConfig(t *testing.T) {
 		})
 	}
 }
+
+func TestExtractFunctionResponseContent(t *testing.T) {
+	tests := []struct {
+		name string
+		resp any
+		want string
+	}{
+		{
+			name: "plain string response",
+			resp: "hello",
+			want: "hello",
+		},
+		{
+			name: "content array with top-level text items",
+			resp: map[string]any{
+				"content": []any{
+					map[string]any{"type": "text", "text": "line1"},
+					map[string]any{"type": "text", "text": "line2"},
+				},
+			},
+			want: "line1\nline2",
+		},
+		{
+			name: "resource content nested under resource.text (GitHub MCP get_file_contents)",
+			resp: map[string]any{
+				"content": []any{
+					map[string]any{"type": "text", "text": "successfully downloaded text file (SHA: abc123)"},
+					map[string]any{
+						"type": "resource",
+						"resource": map[string]any{
+							"uri":  "repo://owner/repo/contents/path.yaml",
+							"text": "p, role:foo-developer, applications, get, *, allow",
+						},
+					},
+				},
+			},
+			want: "successfully downloaded text file (SHA: abc123)\np, role:foo-developer, applications, get, *, allow",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := extractFunctionResponseContent(tt.resp)
+			if got != tt.want {
+				t.Errorf("extractFunctionResponseContent() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}