grafana/public/app/plugins/datasource/stackdriver/partials/annotations.editor.html

<stackdriver-filter target="ctrl.annotation.target" refresh="ctrl.refresh()" datasource="ctrl.datasource"
  default-dropdown-value="ctrl.defaultDropdownValue" default-service-value="ctrl.defaultServiceValue" hide-group-bys="true"></stackdriver-filter>

<div class="gf-form gf-form-inline">
  <div class="gf-form">
    <span class="gf-form-label query-keyword width-9">Title</span>
    <input type="text" class="gf-form-input width-20" ng-model="ctrl.annotation.target.title" />
  </div>
  <div class="gf-form">
    <span class="gf-form-label query-keyword width-9">Text</span>
    <input type="text" class="gf-form-input width-20" ng-model="ctrl.annotation.target.text" />
  </div>
  <div class="gf-form gf-form--grow">
    <div class="gf-form-label gf-form-label--grow"></div>
  </div>
</div>

<div class="gf-form grafana-info-box" style="padding: 0">
  <pre class="gf-form-pre alert alert-info" style="margin-right: 0"><h5>Annotation Query Format</h5>
An annotation is an event that is overlaid on top of graphs. Annotation rendering is expensive so it is important to limit the number of rows returned.

The Title and Text fields support templating and can use data returned from the query. For example, the Title field could have the following text:

<code ng-non-bindable>{{metric.type}} has value: {{metric.value}}</code>

Example Result: <code ng-non-bindable>monitoring.googleapis.com/uptime_check/http_status has this value: 502</code>

<label>Patterns:</label>
<code ng-non-bindable>{{metric.value}}</code> = value of the metric/point
<code ng-non-bindable>{{metric.type}}</code> = metric type e.g. compute.googleapis.com/instance/cpu/usage_time
<code ng-non-bindable>{{metric.name}}</code> = name part of metric e.g. instance/cpu/usage_time
<code ng-non-bindable>{{metric.service}}</code> = service part of metric e.g. compute

<code ng-non-bindable>{{metric.label.label_name}}</code> = Metric label metadata e.g. metric.label.instance_name
<code ng-non-bindable>{{resource.label.label_name}}</code> = Resource label metadata e.g. resource.label.zone
</pre>
</div>