Use labels in Summary vs Description

Hello all! This is my first post in here, so excuse me for any ignorance.
I am using Grafana version 10.4 with Influxdb and Telegraf, with docker compose.

I am currently trying to understand more how alerting works in Grafana and have come upon a puzzling(for me) issue, which is how to access labels in Summary vs Description.
I have a query which returns the mem consumption of some containers, and among other labels there is one called “container_name”.
In order to access this label in the Summary field, I need to use:
{{ .Labels.container_name }}

however, to access the same label in the Description field, I need to use:
{{{ $Labels.container_name }}

Can somebody help me understand, why I need to use dot(.) for Summary and $ for Description? I thought the context for labels should be the same in both, so $ should work for both?

P.s I have tried every other combination in Summary(for example {{ $ }} but none seem to work except using {{ .labels.labelname }}

$labels is official syntax: