tools: nfdc help command

refs #3780

Change-Id: Ibd0e37bad127a38e582864fadd81afadc74baf48
diff --git a/tools/nfdc/command-definition.hpp b/tools/nfdc/command-definition.hpp
index 136f5c4..47c6af3 100644
--- a/tools/nfdc/command-definition.hpp
+++ b/tools/nfdc/command-definition.hpp
@@ -142,20 +142,21 @@
   }
 
 public: // help
-  /** \return one-line synopsis
+  /** \return one-line description
    */
   const std::string&
-  getSynopsis() const
+  getTitle() const
   {
-    return m_synopsis;
+    return m_title;
   }
 
-  /** \brief set one-line synopsis
+  /** \brief set one-line description
+   *  \param title one-line description, written in lower case
    */
   CommandDefinition&
-  setSynopsis(const std::string& synopsis)
+  setTitle(const std::string& title)
   {
-    m_synopsis = synopsis;
+    m_title = title;
     return *this;
   }
 
@@ -189,7 +190,7 @@
   std::string m_noun;
   std::string m_verb;
 
-  std::string m_synopsis;
+  std::string m_title;
 
   struct Arg
   {