diff --git a/meggie/configuration.json b/meggie/configuration.json
index a416d87b..706c6efd 100644
--- a/meggie/configuration.json
+++ b/meggie/configuration.json
@@ -1,4 +1,5 @@
 {
+    "id": "meggie",
     "tabs": [
         {"id": "preprocessing",
          "name": "Preprocessing",
diff --git a/meggie/mainwindow/dynamic.py b/meggie/mainwindow/dynamic.py
index b954dbcc..bd1bf9df 100644
--- a/meggie/mainwindow/dynamic.py
+++ b/meggie/mainwindow/dynamic.py
@@ -51,13 +51,16 @@ def find_all_package_specs():
             continue
         with open(config_path, "r") as f:
             config = json.load(f)
-            if config:
+            if config and config.get("id"):
                 package_specs[source] = config
 
     # add possibly missing fields
     for package_spec in package_specs.values():
         if "name" not in package_spec:
-            package_spec["name"] = ""
+            package_spec["name"] = package_spec["id"]
+
+        if "description" not in package_spec:
+            package_spec["description"] = package_spec.get("name", "")
 
         if "author" not in package_spec:
             package_spec["author"] = ""
@@ -282,11 +285,13 @@ def __init__(self, parent):
 
                 action_spec = self.action_specs[action_name][2]
                 title = action_spec["name"]
+                description = action_spec.get("description", "")
 
                 pushButtonInputActionElement = QtWidgets.QPushButton(
                     self.groupBoxInputActions
                 )
                 pushButtonInputActionElement.setText(title)
+                pushButtonInputActionElement.setToolTip(description)
                 self.gridLayoutInputActions.addWidget(
                     pushButtonInputActionElement, idx, 0, 1, 1
                 )
@@ -310,11 +315,13 @@ def __init__(self, parent):
 
                 action_spec = self.action_specs[action_name][2]
                 title = action_spec["name"]
+                description = action_spec.get("description", "")
 
                 pushButtonOutputActionElement = QtWidgets.QPushButton(
                     self.groupBoxOutputActions
                 )
                 pushButtonOutputActionElement.setText(title)
+                pushButtonOutputActionElement.setToolTip(description)
                 self.gridLayoutOutputActions.addWidget(
                     pushButtonOutputActionElement, idx, 0, 1, 1
                 )
@@ -458,10 +465,12 @@ def connect_to_handler(button, name):
                 def handler_wrapper(checked):
                     experiment = self.parent.experiment
                     if not experiment:
+                        messagebox(self, "You need to open an experiment first.")
                         return
 
                     subject = experiment.active_subject
                     if not subject:
+                        messagebox(self, "You need to activate a subject first.")
                         return
 
                     data = self._get_data()