diff --git a/wlauto/modules/cgroups.py b/wlauto/modules/cgroups.py
index 57a3cfbf..46f836b8 100644
--- a/wlauto/modules/cgroups.py
+++ b/wlauto/modules/cgroups.py
@@ -135,6 +135,12 @@ class CpusetController(CgroupController):
 class Cgroups(Module):
 
     name = 'cgroups'
+    description = """
+    Adds cgroups query and manupution APIs to a Device interface.
+
+    Currently, only cpusets controller is supported.
+
+    """
     capabilities = ['cgroups']
 
     controllers = [
diff --git a/wlauto/modules/cpuidle.py b/wlauto/modules/cpuidle.py
index dca41553..8257a80f 100644
--- a/wlauto/modules/cpuidle.py
+++ b/wlauto/modules/cpuidle.py
@@ -78,6 +78,10 @@ class CpuidleState(object):
 class Cpuidle(Module):
 
     name = 'cpuidle'
+    description = """
+    Adds cpuidle state query and manupution APIs to a Device interface.
+
+    """
     capabilities = ['cpuidle']
 
     root_path = '/sys/devices/system/cpu/cpuidle'