When I was studying for my CELPIP exam I got material from them. Unfortunately, I can not put the PDF to the public because it has a watermark with my personal email. But I can put you here what it says.
CELPIP's twentieth-ninth error as they state:
The CELPIP Speaking Test measures your ability to communicate in spoken English. Test takers are evaluated on many factors, including relevance and depth of meaning. A common error during the Speaking component is replying to test prompts without providing enough descriptive detail.
Test takers who do well on the Speaking Test reply to test prompt directly, but then they go on to support their answers with relevant details. For example, if you are asked to name your favourite season and you reply simply, "summer," your answer would be considered undeveloped and be lacking supporting details You should say why summer is your favourite season and provide a series of examples. For instance, you could say, "I like summer because it's warm and I can be outside more," and so on.
Try to make sure the details you provide in your answers are relevant to the test prompt. No matter how many supporting details you give, if you aren't answering the question asked or following the instructions given, you will lose marks. The best way to stay on topic is to read the test prompt carefully.
It is best not to repeat the same phrase over and over.