diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -233,6 +233,7 @@
     'ConduitException' => 'applications/conduit/protocol/exception/ConduitException.php',
     'ConduitGetCapabilitiesConduitAPIMethod' => 'applications/conduit/method/ConduitGetCapabilitiesConduitAPIMethod.php',
     'ConduitGetCertificateConduitAPIMethod' => 'applications/conduit/method/ConduitGetCertificateConduitAPIMethod.php',
+    'ConduitIntListParameterType' => 'applications/conduit/parametertype/ConduitIntListParameterType.php',
     'ConduitIntParameterType' => 'applications/conduit/parametertype/ConduitIntParameterType.php',
     'ConduitListParameterType' => 'applications/conduit/parametertype/ConduitListParameterType.php',
     'ConduitLogGarbageCollector' => 'applications/conduit/garbagecollector/ConduitLogGarbageCollector.php',
@@ -4085,6 +4086,7 @@
     'ConduitException' => 'Exception',
     'ConduitGetCapabilitiesConduitAPIMethod' => 'ConduitAPIMethod',
     'ConduitGetCertificateConduitAPIMethod' => 'ConduitAPIMethod',
+    'ConduitIntListParameterType' => 'ConduitListParameterType',
     'ConduitIntParameterType' => 'ConduitListParameterType',
     'ConduitListParameterType' => 'ConduitParameterType',
     'ConduitLogGarbageCollector' => 'PhabricatorGarbageCollector',
diff --git a/src/applications/conduit/parametertype/ConduitIntListParameterType.php b/src/applications/conduit/parametertype/ConduitIntListParameterType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/conduit/parametertype/ConduitIntListParameterType.php
@@ -0,0 +1,40 @@
+<?php
+
+final class ConduitIntListParameterType
+  extends ConduitListParameterType {
+
+  protected function getParameterValue(array $request, $key) {
+    $list = parent::getParameterValue($request, $key);
+
+    foreach ($list as $idx => $item) {
+      if (!is_int($item)) {
+        $this->raiseValidationException(
+          $request,
+          $key,
+          pht(
+            'Expected a list of integers, but item with index "%s" is '.
+            'not an integer.',
+            $idx));
+      }
+    }
+
+    return $this->validateIntList($request, $key, $list);
+  }
+
+  protected function getParameterTypeName() {
+    return 'list<int>';
+  }
+
+  protected function getParameterFormatDescriptions() {
+    return array(
+      pht('List of integers.'),
+    );
+  }
+
+  protected function getParameterExamples() {
+    return array(
+      '[123, 0, -456]',
+    );
+  }
+
+}
diff --git a/src/applications/maniphest/query/ManiphestTaskSearchEngine.php b/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
--- a/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
+++ b/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
@@ -48,20 +48,30 @@
       id(new PhabricatorOwnersSearchField())
         ->setLabel(pht('Assigned To'))
         ->setKey('assignedPHIDs')
-        ->setAliases(array('assigned')),
+        ->setConduitKey('assigned')
+        ->setAliases(array('assigned'))
+        ->setDescription(
+          pht('Search for tasks owned by a user from a list.')),
       id(new PhabricatorUsersSearchField())
         ->setLabel(pht('Authors'))
         ->setKey('authorPHIDs')
-        ->setAliases(array('author', 'authors')),
+        ->setAliases(array('author', 'authors'))
+        ->setDescription(
+          pht('Search for tasks with given authors.')),
       id(new PhabricatorSearchDatasourceField())
         ->setLabel(pht('Statuses'))
         ->setKey('statuses')
         ->setAliases(array('status'))
+        ->setDescription(
+          pht('Search for tasks with given statuses.'))
         ->setDatasource(new ManiphestTaskStatusFunctionDatasource()),
       id(new PhabricatorSearchDatasourceField())
         ->setLabel(pht('Priorities'))
         ->setKey('priorities')
         ->setAliases(array('priority'))
+        ->setDescription(
+          pht('Search for tasks with given priorities.'))
+        ->setConduitParameterType(new ConduitIntListParameterType())
         ->setDatasource(new ManiphestTaskPriorityDatasource()),
       id(new PhabricatorSearchTextField())
         ->setLabel(pht('Contains Words'))
diff --git a/src/applications/owners/searchfield/PhabricatorOwnersSearchField.php b/src/applications/owners/searchfield/PhabricatorOwnersSearchField.php
--- a/src/applications/owners/searchfield/PhabricatorOwnersSearchField.php
+++ b/src/applications/owners/searchfield/PhabricatorOwnersSearchField.php
@@ -15,4 +15,8 @@
     return new PhabricatorPeopleOwnerDatasource();
   }
 
+  protected function newConduitParameterType() {
+    return new ConduitUserListParameterType();
+  }
+
 }
diff --git a/src/applications/search/field/PhabricatorSearchDatasourceField.php b/src/applications/search/field/PhabricatorSearchDatasourceField.php
--- a/src/applications/search/field/PhabricatorSearchDatasourceField.php
+++ b/src/applications/search/field/PhabricatorSearchDatasourceField.php
@@ -4,6 +4,7 @@
   extends PhabricatorSearchTokenizerField {
 
   private $datasource;
+  private $conduitParameterType;
 
   protected function newDatasource() {
     return id(clone $this->datasource);
@@ -14,8 +15,17 @@
     return $this;
   }
 
+  public function setConduitParameterType(ConduitParameterType $type) {
+    $this->conduitParameterType = $type;
+    return $this;
+  }
+
   protected function newConduitParameterType() {
-    return new ConduitStringListParameterType();
+    if (!$this->conduitParameterType) {
+      return new ConduitStringListParameterType();
+    }
+
+    return $this->conduitParameterType;
   }
 
 }