diff --git a/src/plugins/bazaar/bazaarplugin.cpp b/src/plugins/bazaar/bazaarplugin.cpp
index cc7e3d4cfb7..307c0929aa7 100644
--- a/src/plugins/bazaar/bazaarplugin.cpp
+++ b/src/plugins/bazaar/bazaarplugin.cpp
@@ -319,6 +319,7 @@ BazaarPluginPrivate::BazaarPluginPrivate()
 
     const QString prefix = QLatin1String("bzr");
     m_commandLocator = new CommandLocator("Bazaar", prefix, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a Bazaar version control operation."));
 
     // Create menu item for Bazaar
     m_bazaarContainer = ActionManager::createMenu("Bazaar.BazaarMenu");
diff --git a/src/plugins/bookmarks/bookmarkfilter.cpp b/src/plugins/bookmarks/bookmarkfilter.cpp
index c62cf7edc80..28173ffe5d1 100644
--- a/src/plugins/bookmarks/bookmarkfilter.cpp
+++ b/src/plugins/bookmarks/bookmarkfilter.cpp
@@ -39,6 +39,8 @@ BookmarkFilter::BookmarkFilter(BookmarkManager *manager)
 {
     setId("Bookmarks");
     setDisplayName(tr("Bookmarks"));
+    setDescription(tr("Matches all bookmarks. Filter by file name, by the text on the line of the "
+                      "bookmark, or by the bookmark's note text."));
     setPriority(Medium);
     setDefaultShortcutString("b");
 }
diff --git a/src/plugins/clearcase/clearcaseplugin.cpp b/src/plugins/clearcase/clearcaseplugin.cpp
index be4464181c3..8b0589b533b 100644
--- a/src/plugins/clearcase/clearcaseplugin.cpp
+++ b/src/plugins/clearcase/clearcaseplugin.cpp
@@ -660,6 +660,7 @@ ClearCasePluginPrivate::ClearCasePluginPrivate()
     const QString prefix = QLatin1String("cc");
     // register cc prefix in Locator
     m_commandLocator = new CommandLocator("cc", description, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a ClearCase version control operation."));
 
     //register actions
     ActionContainer *toolsContainer = ActionManager::actionContainer(M_TOOLS);
diff --git a/src/plugins/cmakeprojectmanager/cmakelocatorfilter.cpp b/src/plugins/cmakeprojectmanager/cmakelocatorfilter.cpp
index abeec70e594..1db3ab929b5 100644
--- a/src/plugins/cmakeprojectmanager/cmakelocatorfilter.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakelocatorfilter.cpp
@@ -116,6 +116,7 @@ BuildCMakeTargetLocatorFilter::BuildCMakeTargetLocatorFilter()
 {
     setId("Build CMake target");
     setDisplayName(tr("Build CMake target"));
+    setDescription(tr("Builds a target of any open CMake project."));
     setDefaultShortcutString("cm");
     setPriority(High);
 }
@@ -165,6 +166,7 @@ OpenCMakeTargetLocatorFilter::OpenCMakeTargetLocatorFilter()
 {
     setId("Open CMake target definition");
     setDisplayName(tr("Open CMake target"));
+    setDescription(tr("Jumps to the definition of a target of any open CMake project."));
     setDefaultShortcutString("cmo");
     setPriority(Medium);
 }
diff --git a/src/plugins/coreplugin/locator/directoryfilter.cpp b/src/plugins/coreplugin/locator/directoryfilter.cpp
index 6a730b0e07c..69ddfc2eb3e 100644
--- a/src/plugins/coreplugin/locator/directoryfilter.cpp
+++ b/src/plugins/coreplugin/locator/directoryfilter.cpp
@@ -67,6 +67,9 @@ DirectoryFilter::DirectoryFilter(Id id)
     setId(id);
     setDefaultIncludedByDefault(true);
     setDisplayName(defaultDisplayName());
+    setDescription(tr("Matches all files from a custom set of directories. Append \"+<number>\" or "
+                      "\":<number>\" to jump to the given line number. Append another "
+                      "\"+<number>\" or \":<number>\" to jump to the column number as well."));
 }
 
 void DirectoryFilter::saveState(QJsonObject &object) const
diff --git a/src/plugins/coreplugin/locator/executefilter.cpp b/src/plugins/coreplugin/locator/executefilter.cpp
index 6110f13f713..be0af47dde8 100644
--- a/src/plugins/coreplugin/locator/executefilter.cpp
+++ b/src/plugins/coreplugin/locator/executefilter.cpp
@@ -38,6 +38,9 @@ ExecuteFilter::ExecuteFilter()
 {
     setId("Execute custom commands");
     setDisplayName(tr("Execute Custom Commands"));
+    setDescription(tr(
+        "Runs an arbitrary command with arguments. The command is searched for in the PATH "
+        "environment variable if needed. Note that the command is run directly, not in a shell."));
     setDefaultShortcutString("!");
     setPriority(High);
     setDefaultIncludedByDefault(false);
diff --git a/src/plugins/coreplugin/locator/externaltoolsfilter.cpp b/src/plugins/coreplugin/locator/externaltoolsfilter.cpp
index 11e142f47ba..159af87cafc 100644
--- a/src/plugins/coreplugin/locator/externaltoolsfilter.cpp
+++ b/src/plugins/coreplugin/locator/externaltoolsfilter.cpp
@@ -37,6 +37,8 @@ ExternalToolsFilter::ExternalToolsFilter()
 {
     setId("Run external tool");
     setDisplayName(tr("Run External Tool"));
+    setDescription(tr("Runs an external tool that you have set up in the options (Environment > "
+                      "External Tools)."));
     setDefaultShortcutString("x");
     setPriority(Medium);
 }
diff --git a/src/plugins/coreplugin/locator/filesystemfilter.cpp b/src/plugins/coreplugin/locator/filesystemfilter.cpp
index 118ebb25325..83d67a768bd 100644
--- a/src/plugins/coreplugin/locator/filesystemfilter.cpp
+++ b/src/plugins/coreplugin/locator/filesystemfilter.cpp
@@ -66,6 +66,9 @@ FileSystemFilter::FileSystemFilter()
 {
     setId("Files in file system");
     setDisplayName(tr("Files in File System"));
+    setDescription(tr("Opens a file given by a relative path to the current document, or absolute "
+                      "path. \"~\" refers to your home directory. You have the option to create a "
+                      "file if it does not exist yet."));
     setDefaultShortcutString("f");
     setDefaultIncludedByDefault(false);
 }
diff --git a/src/plugins/coreplugin/locator/ilocatorfilter.cpp b/src/plugins/coreplugin/locator/ilocatorfilter.cpp
index 66a2b86e2cd..aee4fe49065 100644
--- a/src/plugins/coreplugin/locator/ilocatorfilter.cpp
+++ b/src/plugins/coreplugin/locator/ilocatorfilter.cpp
@@ -459,6 +459,26 @@ void ILocatorFilter::setDisplayName(const QString &displayString)
     m_displayName = displayString;
 }
 
+/*!
+    Returns a longer, human-readable description of what the filter does.
+
+    \sa setDescription()
+*/
+QString ILocatorFilter::description() const
+{
+    return m_description;
+}
+
+/*!
+    Sets the longer, human-readable \a description of what the filter does.
+
+    \sa description()
+*/
+void ILocatorFilter::setDescription(const QString &description)
+{
+    m_description = description;
+}
+
 /*!
     Sets whether the filter provides a configuration dialog to \a configurable.
     Most filters should at least provide the default dialog.
diff --git a/src/plugins/coreplugin/locator/ilocatorfilter.h b/src/plugins/coreplugin/locator/ilocatorfilter.h
index 7bf15d284b3..0e07b7482e2 100644
--- a/src/plugins/coreplugin/locator/ilocatorfilter.h
+++ b/src/plugins/coreplugin/locator/ilocatorfilter.h
@@ -132,6 +132,9 @@ public:
     QString displayName() const;
     void setDisplayName(const QString &displayString);
 
+    QString description() const;
+    void setDescription(const QString &description);
+
     Priority priority() const;
 
     QString shortcutString() const;
@@ -193,6 +196,7 @@ private:
     QString m_shortcut;
     Priority m_priority = Medium;
     QString m_displayName;
+    QString m_description;
     QString m_defaultShortcut;
     bool m_defaultIncludedByDefault = false;
     bool m_includedByDefault = m_defaultIncludedByDefault;
diff --git a/src/plugins/coreplugin/locator/javascriptfilter.cpp b/src/plugins/coreplugin/locator/javascriptfilter.cpp
index 952cd0d094b..257f133dda8 100644
--- a/src/plugins/coreplugin/locator/javascriptfilter.cpp
+++ b/src/plugins/coreplugin/locator/javascriptfilter.cpp
@@ -38,6 +38,7 @@ JavaScriptFilter::JavaScriptFilter()
 {
     setId("JavaScriptFilter");
     setDisplayName(tr("Evaluate JavaScript"));
+    setDescription(tr("Evaluates arbitrary JavaScript expressions and copies the result."));
     setDefaultIncludedByDefault(false);
     setDefaultShortcutString("=");
     m_abortTimer.setSingleShot(true);
diff --git a/src/plugins/coreplugin/locator/locator.cpp b/src/plugins/coreplugin/locator/locator.cpp
index 670f77e2013..8db747845ca 100644
--- a/src/plugins/coreplugin/locator/locator.cpp
+++ b/src/plugins/coreplugin/locator/locator.cpp
@@ -250,6 +250,7 @@ void Locator::updateFilterActions()
             action = actionCopy.take(filterId);
             action->setText(filter->displayName());
         }
+        action->setToolTip(filter->description());
         m_filterActionMap.insert(filterId, action);
     }
 
diff --git a/src/plugins/coreplugin/locator/locatorsettingspage.cpp b/src/plugins/coreplugin/locator/locatorsettingspage.cpp
index 02ddbf6337c..e0c569d05e1 100644
--- a/src/plugins/coreplugin/locator/locatorsettingspage.cpp
+++ b/src/plugins/coreplugin/locator/locatorsettingspage.cpp
@@ -111,6 +111,9 @@ QVariant FilterItem::data(int column, int role) const
     default:
         break;
     }
+
+    if (role == Qt::ToolTipRole)
+        return m_filter->description();
     return QVariant();
 }
 
diff --git a/src/plugins/coreplugin/locator/spotlightlocatorfilter.cpp b/src/plugins/coreplugin/locator/spotlightlocatorfilter.cpp
index f333d11b301..748ed17330e 100644
--- a/src/plugins/coreplugin/locator/spotlightlocatorfilter.cpp
+++ b/src/plugins/coreplugin/locator/spotlightlocatorfilter.cpp
@@ -241,6 +241,10 @@ SpotlightLocatorFilter::SpotlightLocatorFilter()
     setDefaultShortcutString("md");
     setDefaultIncludedByDefault(false);
     setDisplayName(tr("File Name Index"));
+    setDescription(
+        tr("Matches files from a global file system index (Spotlight, Locate, Everything). Append "
+           "\"+<number>\" or \":<number>\" to jump to the given line number. Append another "
+           "\"+<number>\" or \":<number>\" to jump to the column number as well."));
     setConfigurable(true);
     reset();
 }
diff --git a/src/plugins/coreplugin/menubarfilter.cpp b/src/plugins/coreplugin/menubarfilter.cpp
index ad8f904148d..354a0e7b367 100644
--- a/src/plugins/coreplugin/menubarfilter.cpp
+++ b/src/plugins/coreplugin/menubarfilter.cpp
@@ -54,6 +54,9 @@ MenuBarFilter::MenuBarFilter()
 {
     setId("Actions from the menu");
     setDisplayName(tr("Actions from the Menu"));
+    setDescription(
+        tr("Triggers an action from the menu. Matches any part of a menu hierarchy, separated by "
+           "\">\". For example \"sess def\" matches \"File > Sessions > Default\"."));
     setDefaultShortcutString("t");
     connect(ICore::instance(), &ICore::contextAboutToChange, this, [this] {
         if (LocatorManager::locatorHasFocus())
diff --git a/src/plugins/cpptools/cppincludesfilter.cpp b/src/plugins/cpptools/cppincludesfilter.cpp
index 32eef13349d..57a1b6b47f8 100644
--- a/src/plugins/cpptools/cppincludesfilter.cpp
+++ b/src/plugins/cpptools/cppincludesfilter.cpp
@@ -121,6 +121,10 @@ CppIncludesFilter::CppIncludesFilter()
 {
     setId(Constants::INCLUDES_FILTER_ID);
     setDisplayName(Constants::INCLUDES_FILTER_DISPLAY_NAME);
+    setDescription(
+        tr("Matches all files that are included by all C++ files in all projects. Append "
+           "\"+<number>\" or \":<number>\" to jump to the given line number. Append another "
+           "\"+<number>\" or \":<number>\" to jump to the column number as well."));
     setDefaultShortcutString("ai");
     setDefaultIncludedByDefault(true);
     setPriority(ILocatorFilter::Low);
diff --git a/src/plugins/cvs/cvsplugin.cpp b/src/plugins/cvs/cvsplugin.cpp
index 85d3598ce44..46f88ea9b78 100644
--- a/src/plugins/cvs/cvsplugin.cpp
+++ b/src/plugins/cvs/cvsplugin.cpp
@@ -546,6 +546,7 @@ CvsPluginPrivate::CvsPluginPrivate()
 
     const QString prefix = QLatin1String("cvs");
     m_commandLocator = new CommandLocator("CVS", prefix, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a CVS version control operation."));
 
     // Register actions
     ActionContainer *toolsContainer = ActionManager::actionContainer(M_TOOLS);
diff --git a/src/plugins/git/gitplugin.cpp b/src/plugins/git/gitplugin.cpp
index 4caaddbbe16..254263203f1 100644
--- a/src/plugins/git/gitplugin.cpp
+++ b/src/plugins/git/gitplugin.cpp
@@ -662,6 +662,7 @@ GitPluginPrivate::GitPluginPrivate()
 
     const QString prefix = "git";
     m_commandLocator = new CommandLocator("Git", prefix, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a Git version control operation."));
 
     //register actions
     ActionContainer *toolsContainer = ActionManager::actionContainer(Core::Constants::M_TOOLS);
diff --git a/src/plugins/languageclient/locatorfilter.cpp b/src/plugins/languageclient/locatorfilter.cpp
index c26faf90af2..9a0c304b0b0 100644
--- a/src/plugins/languageclient/locatorfilter.cpp
+++ b/src/plugins/languageclient/locatorfilter.cpp
@@ -47,6 +47,8 @@ DocumentLocatorFilter::DocumentLocatorFilter()
 {
     setId(Constants::LANGUAGECLIENT_DOCUMENT_FILTER_ID);
     setDisplayName(Constants::LANGUAGECLIENT_DOCUMENT_FILTER_DISPLAY_NAME);
+    setDescription(
+        tr("Matches all symbols from the current document, based on a language server."));
     setDefaultShortcutString(".");
     setDefaultIncludedByDefault(false);
     setPriority(ILocatorFilter::Low);
diff --git a/src/plugins/macros/macrolocatorfilter.cpp b/src/plugins/macros/macrolocatorfilter.cpp
index 98d69a24e9f..35b238454b7 100644
--- a/src/plugins/macros/macrolocatorfilter.cpp
+++ b/src/plugins/macros/macrolocatorfilter.cpp
@@ -42,6 +42,8 @@ MacroLocatorFilter::MacroLocatorFilter()
 {
     setId("Macros");
     setDisplayName(tr("Text Editing Macros"));
+    setDescription(tr("Runs a text editing macro that was recorded with Tools > Text Editing "
+                      "Macros > Record Macro."));
     setDefaultShortcutString("rm");
 }
 
diff --git a/src/plugins/mercurial/mercurialplugin.cpp b/src/plugins/mercurial/mercurialplugin.cpp
index 8140bebeede..9b208283add 100644
--- a/src/plugins/mercurial/mercurialplugin.cpp
+++ b/src/plugins/mercurial/mercurialplugin.cpp
@@ -279,6 +279,7 @@ MercurialPluginPrivate::MercurialPluginPrivate()
 
     const QString prefix = QLatin1String("hg");
     m_commandLocator = new Core::CommandLocator("Mercurial", prefix, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a Mercurial version control operation."));
 
     createMenu(context);
 }
diff --git a/src/plugins/perforce/perforceplugin.cpp b/src/plugins/perforce/perforceplugin.cpp
index 5eaa7fb6a64..831d9f47107 100644
--- a/src/plugins/perforce/perforceplugin.cpp
+++ b/src/plugins/perforce/perforceplugin.cpp
@@ -400,6 +400,7 @@ PerforcePluginPrivate::PerforcePluginPrivate()
 
     const QString prefix = QLatin1String("p4");
     m_commandLocator = new CommandLocator("Perforce", prefix, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a Perforce version control operation."));
 
     ActionContainer *mtools = ActionManager::actionContainer(Core::Constants::M_TOOLS);
 
diff --git a/src/plugins/projectexplorer/allprojectsfilter.cpp b/src/plugins/projectexplorer/allprojectsfilter.cpp
index 5367c045104..d0c3e8cade6 100644
--- a/src/plugins/projectexplorer/allprojectsfilter.cpp
+++ b/src/plugins/projectexplorer/allprojectsfilter.cpp
@@ -38,6 +38,9 @@ AllProjectsFilter::AllProjectsFilter()
 {
     setId("Files in any project");
     setDisplayName(tr("Files in Any Project"));
+    setDescription(tr("Matches all files of all open projects. Append \"+<number>\" or "
+                      "\":<number>\" to jump to the given line number. Append another "
+                      "\"+<number>\" or \":<number>\" to jump to the column number as well."));
     setDefaultShortcutString("a");
     setDefaultIncludedByDefault(true);
 
diff --git a/src/plugins/projectexplorer/currentprojectfilter.cpp b/src/plugins/projectexplorer/currentprojectfilter.cpp
index 59a3b5c3bf1..61098b9d841 100644
--- a/src/plugins/projectexplorer/currentprojectfilter.cpp
+++ b/src/plugins/projectexplorer/currentprojectfilter.cpp
@@ -38,6 +38,9 @@ CurrentProjectFilter::CurrentProjectFilter()
 {
     setId("Files in current project");
     setDisplayName(tr("Files in Current Project"));
+    setDescription(tr("Matches all files from the current document's project. Append \"+<number>\" "
+                      "or \":<number>\" to jump to the given line number. Append another "
+                      "\"+<number>\" or \":<number>\" to jump to the column number as well."));
     setDefaultShortcutString("p");
     setDefaultIncludedByDefault(false);
 
diff --git a/src/plugins/subversion/subversionplugin.cpp b/src/plugins/subversion/subversionplugin.cpp
index bdf7400b8d9..9016719b9b4 100644
--- a/src/plugins/subversion/subversionplugin.cpp
+++ b/src/plugins/subversion/subversionplugin.cpp
@@ -402,6 +402,7 @@ SubversionPluginPrivate::SubversionPluginPrivate()
 
     const QString prefix = QLatin1String("svn");
     m_commandLocator = new CommandLocator("Subversion", prefix, prefix, this);
+    m_commandLocator->setDescription(tr("Triggers a Subversion version control operation."));
 
     // Register actions
     ActionContainer *toolsContainer = ActionManager::actionContainer(M_TOOLS);
diff --git a/src/plugins/texteditor/linenumberfilter.cpp b/src/plugins/texteditor/linenumberfilter.cpp
index dc1f6298c2d..7695bbd39d7 100644
--- a/src/plugins/texteditor/linenumberfilter.cpp
+++ b/src/plugins/texteditor/linenumberfilter.cpp
@@ -48,6 +48,7 @@ LineNumberFilter::LineNumberFilter(QObject *parent)
 {
     setId("Line in current document");
     setDisplayName(tr("Line in Current Document"));
+    setDescription(tr("Jumps to the given line in the current document."));
     setPriority(High);
     setDefaultShortcutString("l");
     setDefaultIncludedByDefault(true);