diff --git a/README.md b/README.md
index 188f058..1ff0150 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,14 @@ By default, it will enable all ROS tracepoints and a few kernel tracepoints. The
 
 ### Launch file trace action
 
-Another option is to use the `Trace` action in a launch file along with your `Node` action(s).
+Another option is to use the `Trace` action in a launch file along with your `Node` action(s). This way, tracing happens when launching the launch file.
+
+```
+$ ros2 launch tracetools_launch example.launch.py
+```
 
 See [this example launch file](./tracetools_launch/launch/example.launch.py) for more information.
+
+## Design
+
+See the [design document](./doc/design_ros_2.md).
diff --git a/doc/design_ros_2.md b/doc/design_ros_2.md
index fe08a32..38fefce 100644
--- a/doc/design_ros_2.md
+++ b/doc/design_ros_2.md
@@ -575,6 +575,12 @@ We could look into making analyses work on both ROS 1 and ROS 2, through a commo
         * convert CTF traces to pickle files
         * wrap trace events in Python `dict`
         * handle and process trace events to gather data
+* `ros2trace_analysis`
+    * provides a `ros2cli` extension with verbs
+    `$ ros2 trace-analysis`
+        * uses `tracetools_analysis` functions
+        `$ ros2 trace-analysis convert`
+        `$ ros2 trace-analysis process`
 
 ```plantuml
 @startuml
@@ -633,6 +639,11 @@ tracetools_read <-- tracetools_analysis
 pandas <--- tracetools_analysis
 bokeh <--- tracetools_analysis
 
+package ros2trace_analysis <<Rectangle>> {
+}
+ros2cli <|-- ros2trace_analysis
+tracetools_analysis <-- ros2trace_analysis
+
 @enduml
 ```
 
diff --git a/tracetools_read/tracetools_read/trace.py b/tracetools_read/tracetools_read/trace.py
index 02d2c27..73ae513 100644
--- a/tracetools_read/tracetools_read/trace.py
+++ b/tracetools_read/tracetools_read/trace.py
@@ -14,6 +14,7 @@
 
 """Module with functions for reading traces."""
 
+import os
 from typing import Iterable
 from typing import List
 
@@ -25,6 +26,22 @@ from . import DictEvent
 BabeltraceEvent = babeltrace.babeltrace.Event
 
 
+def is_trace_directory(path: str) -> bool:
+    """
+    Check recursively if a path is a trace directory.
+
+    :param path: the path to check
+    :return: `True` if it is a trace directory, `False` otherwise
+    """
+    path = os.path.expanduser(path)
+    if not os.path.isdir(path):
+        return False
+    tc = babeltrace.TraceCollection()
+    # Could still return an empty dict even if it is not a trace directory (recursively)
+    traces = tc.add_traces_recursive(path, 'ctf')
+    return traces is not None and len(traces) > 0
+
+
 def get_trace_ctf_events(trace_directory: str) -> Iterable[BabeltraceEvent]:
     """
     Get the events of a trace.
diff --git a/tracetools_trace/tracetools_trace/tools/args.py b/tracetools_trace/tracetools_trace/tools/args.py
index dc56bb3..2088676 100644
--- a/tracetools_trace/tracetools_trace/tools/args.py
+++ b/tracetools_trace/tracetools_trace/tools/args.py
@@ -40,26 +40,27 @@ def parse_args():
 
 def add_arguments(parser):
     parser.add_argument(
-        '--session-name', '-s', dest='session_name',
+        '-s', '--session-name', dest='session_name',
         default=path.append_timestamp('session'),
         help='the name of the tracing session (default: session-YYYYMMDDHHMMSS)')
     parser.add_argument(
-        '--path', '-p', dest='path',
+        '-p', '--path', dest='path',
         default=path.DEFAULT_BASE_PATH,
         help='path of the base directory for trace data (default: %(default)s)')
     arg = parser.add_argument(
-        '--ust', '-u', nargs='*', dest='events_ust', default=names.DEFAULT_EVENTS_ROS,
+        '-u', '--ust', nargs='*', dest='events_ust',
+        default=names.DEFAULT_EVENTS_ROS,
         help='the ROS UST events to enable (default: all events) '
              '[to disable all UST events, '
              'provide this flag without any event name]')
     arg.completer = DefaultArgValueCompleter(arg)
     arg = parser.add_argument(
-        '--kernel', '-k', nargs='*', dest='events_kernel',
+        '-k', '--kernel', nargs='*', dest='events_kernel',
         default=names.DEFAULT_EVENTS_KERNEL,
         help='the kernel events to enable (default: all events) '
              '[to disable all kernel events, '
              'provide this flag without any event name]')
     arg.completer = DefaultArgValueCompleter(arg)
     parser.add_argument(
-        '--list', '-l', dest='list', action='store_true',
+        '-l', '--list', dest='list', action='store_true',
         help='display lists of enabled events (default: %(default)s)')