diff --git a/x-pack/plugins/endpoint/public/applications/endpoint/mocks.ts b/x-pack/plugins/endpoint/public/applications/endpoint/mocks.ts
index 86431139a0389..e1a90b4a416dc 100644
--- a/x-pack/plugins/endpoint/public/applications/endpoint/mocks.ts
+++ b/x-pack/plugins/endpoint/public/applications/endpoint/mocks.ts
@@ -27,10 +27,16 @@ type DataMock = Omit<DataPublicStartMock, 'indexPatterns' | 'query'> & {
   };
 };
 
+/**
+ * Type for our app's depsStart (plugin start dependencies)
+ */
 export interface DepsStartMock {
   data: DataMock;
 }
 
+/**
+ * Returns a mock of our app's depsStart (plugin start dependencies)
+ */
 export const depsStartMock: () => DepsStartMock = () => {
   const dataMock: DataMock = (dataPluginMock.createStartContract() as unknown) as DataMock;
   dataMock.indexPatterns.getFieldsForWildcard = jest.fn();
diff --git a/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/middleware.ts b/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/middleware.ts
index 67de586d13f06..b37ba0c0983d3 100644
--- a/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/middleware.ts
+++ b/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/middleware.ts
@@ -15,8 +15,6 @@ import { EndpointAppConstants } from '../../../../../common/types';
 export const alertMiddlewareFactory: MiddlewareFactory<AlertListState> = (coreStart, depsStart) => {
   async function fetchIndexPatterns(): Promise<IIndexPattern[]> {
     const { indexPatterns } = depsStart.data;
-    // TODO: what's the best way to get the index pattern?
-    // const pattern = await indexPatterns.get('287e7b60-4394-11ea-aaac-c76376668d76');
     const indexName = EndpointAppConstants.ALERT_INDEX_NAME;
     const fields = await indexPatterns.getFieldsForWildcard({ pattern: indexName });
     const indexPattern: IIndexPattern = {
@@ -31,7 +29,6 @@ export const alertMiddlewareFactory: MiddlewareFactory<AlertListState> = (coreSt
     next(action);
     const state = api.getState();
     if (action.type === 'userChangedUrl' && isOnAlertPage(state)) {
-      // TODO: only fetch index pattern once when the page loads
       const patterns = await fetchIndexPatterns();
       api.dispatch({ type: 'serverReturnedSearchBarIndexPatterns', payload: patterns });
 
diff --git a/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/selectors.ts b/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/selectors.ts
index b562bfc67e81c..68731bb3f307f 100644
--- a/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/selectors.ts
+++ b/x-pack/plugins/endpoint/public/applications/endpoint/store/alerts/selectors.ts
@@ -78,6 +78,10 @@ export const uiQueryParams: (
   }
 );
 
+/**
+ * Parses the ui query params and returns a object that represents the query used by the SearchBar component.
+ * If the query url param is undefined, a default is returned.
+ */
 export const searchBarQuery: (state: AlertListState) => Query = createSelector(
   uiQueryParams,
   ({ query }) => {
@@ -89,17 +93,24 @@ export const searchBarQuery: (state: AlertListState) => Query = createSelector(
   }
 );
 
+/**
+ * Parses the ui query params and returns a rison encoded string that represents the search bar's date range.
+ * A default is provided if 'date_range' is not present in the url params.
+ */
 export const encodedSearchBarDateRange: (state: AlertListState) => string = createSelector(
   uiQueryParams,
   ({ date_range: dateRange }) => {
     if (dateRange === undefined) {
-      return encode({ from: 'now-15m', to: 'now' });
+      return encode({ from: 'now-24h', to: 'now' });
     } else {
       return dateRange;
     }
   }
 );
 
+/**
+ * Parses the ui query params and returns a object that represents the dateRange used by the SearchBar component.
+ */
 export const searchBarDateRange: (state: AlertListState) => TimeRange = createSelector(
   encodedSearchBarDateRange,
   encodedDateRange => {
@@ -107,6 +118,10 @@ export const searchBarDateRange: (state: AlertListState) => TimeRange = createSe
   }
 );
 
+/**
+ * Parses the ui query params and returns an array of filters used by the SearchBar component.
+ * If the 'filters' param is not present, a default is returned.
+ */
 export const searchBarFilters: (state: AlertListState) => Filter[] = createSelector(
   uiQueryParams,
   ({ filters }) => {
@@ -118,6 +133,11 @@ export const searchBarFilters: (state: AlertListState) => Filter[] = createSelec
   }
 );
 
+/**
+ * Returns the indexPatterns used by the SearchBar component
+ */
+export const searchBarIndexPatterns = (state: AlertListState) => state.searchBar.patterns;
+
 /**
  * query params to use when requesting alert data.
  */
@@ -157,5 +177,3 @@ export const selectedAlertIsLegacyEndpointEvent: (
   }
   return 'endgame' in event;
 });
-
-export const searchBarIndexPatterns = (state: AlertListState) => state.searchBar.patterns;
diff --git a/x-pack/plugins/endpoint/public/applications/endpoint/store/index.ts b/x-pack/plugins/endpoint/public/applications/endpoint/store/index.ts
index 08e8625d2c08b..f275fbcbbb5e6 100644
--- a/x-pack/plugins/endpoint/public/applications/endpoint/store/index.ts
+++ b/x-pack/plugins/endpoint/public/applications/endpoint/store/index.ts
@@ -49,11 +49,17 @@ export const substateMiddlewareFactory = <Substate>(
   };
 };
 
+/**
+ * @param middlewareDeps Optionally create the store without any middleware. This is useful for testing the store w/o side effects.
+ */
 export const appStoreFactory: (middlewareDeps?: {
   /**
    * Allow middleware to communicate with Kibana core.
    */
   coreStart: CoreStart;
+  /**
+   * Give middleware access to plugin start dependencies.
+   */
   depsStart: EndpointPluginStartDependencies;
 }) => Store = middlewareDeps => {
   let middleware;
diff --git a/x-pack/plugins/endpoint/public/applications/endpoint/types.ts b/x-pack/plugins/endpoint/public/applications/endpoint/types.ts
index 8d52012accffe..3b70a580436fe 100644
--- a/x-pack/plugins/endpoint/public/applications/endpoint/types.ts
+++ b/x-pack/plugins/endpoint/public/applications/endpoint/types.ts
@@ -129,7 +129,7 @@ export interface AlertListState {
   /** Specific Alert data to be shown in the details view */
   readonly alertDetails?: Immutable<AlertData>;
 
-  /** Search bar filters, query, dateRange, and index */
+  /** Search bar state including indexPatterns */
   readonly searchBar: AlertsSearchBarState;
 }