How can I render a tooltip / hint button in Magento 2 Module Configuration?

Question

How can I create a tooltip button in the configuration section of a custom module? Is it possible to use UI Components to define it?

What I'd like to achieve is for example

for the field defined in /etc/adminhtml/system.xml

        <field id="xml_filename" translate="label" type="text" sortOrder="15" showInDefault="1" showInStore="1" showInWebsite="1">
            <label>XML Filename</label>
        </field>

to add a hint

The file will be saved under directory ..... etc etc 

I haven't noticed any such hints in other default magento modules' configuration tabs for reference.

Answer 1

You can use <tooltip> tag for this.

<tooltip>The file will be saved under directory ..... etc etc</tooltip>

For example,

              <field id="test" translate="label" type="text" sortOrder="100" showInDefault="1" showInWebsite="1">
                    <label>Test Textbox</label>
                    <tooltip>The file will be saved under directory ..... etc etc</tooltip>
                </field>

You can find in core magento from below path,

app\code\Magento\Paypal\etc\adminhtml\system\express_checkout.xml

Sample output

Answer 2

You can either use Tooltip

<field id="xml_filename" translate="label" type="text" sortOrder="15" showInDefault="1" showInStore="1" showInWebsite="1">
    <label>XML Filename</label>
    <tooltip>The file will be saved under directory ..... etc etc </tooltip>
</field>

Or Comment

<field id="xml_filename" translate="label" type="text" sortOrder="15" showInDefault="1" showInStore="1" showInWebsite="1">
    <label>XML Filename</label>
    <comment>The file will be saved under directory ..... etc etc </comment>
</field>