diff --git a/src/libmain/common-args.cc b/src/libmain/common-args.cc
index 9151a0344..3e4e475e5 100644
--- a/src/libmain/common-args.cc
+++ b/src/libmain/common-args.cc
@@ -44,7 +44,7 @@ MixCommonArgs::MixCommonArgs(const string & programName)
                 globalConfig.getSettings(settings);
                 for (auto & s : settings)
                     if (hasPrefix(s.first, prefix))
-                        completions->add(s.first, s.second.description);
+                        completions->add(s.first, fmt("Set the `%s` setting.", s.first));
             }
         }
     });
diff --git a/src/libutil/config.cc b/src/libutil/config.cc
index 116dd6bfe..be957dfe3 100644
--- a/src/libutil/config.cc
+++ b/src/libutil/config.cc
@@ -200,7 +200,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
 {
     args.addFlag({
         .longName = name,
-        .description = description,
+        .description = fmt("Set the `%s` setting.", name),
         .category = category,
         .labels = {"value"},
         .handler = {[=](std::string s) { overriden = true; set(s); }},
@@ -209,7 +209,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
     if (isAppendable())
         args.addFlag({
             .longName = "extra-" + name,
-            .description = description,
+            .description = fmt("Append to the `%s` setting.", name),
             .category = category,
             .labels = {"value"},
             .handler = {[=](std::string s) { overriden = true; set(s, true); }},
@@ -260,13 +260,13 @@ template<> void BaseSetting<bool>::convertToArg(Args & args, const std::string &
 {
     args.addFlag({
         .longName = name,
-        .description = description,
+        .description = fmt("Enable the `%s` setting.", name),
         .category = category,
         .handler = {[=]() { override(true); }}
     });
     args.addFlag({
         .longName = "no-" + name,
-        .description = description,
+        .description = fmt("Disable the `%s` setting.", name),
         .category = category,
         .handler = {[=]() { override(false); }}
     });