How to Get Better NotebookLM Video Overviews with Prompt Tweaks
The default NotebookLM Video Overviews output is competent and forgettable. Same host energy, same structure: intro, five points, recap. If every video from your team sounds identical, the problem is not the model — it is that nobody is using the prompt box.
This guide is for people who already generated a few and want output that actually fits a use case. Six adjustments, ordered by how much they change the result.
Why do custom prompts change the video so much?
The generation prompt sets both the script and the visual plan. NotebookLM reads it as the audience brief. Give it a role and a goal, and the model drops the generic survey tone. “Explain the key findings to a busy executive” and “Explain the key findings” are not the same request, and the videos prove it.
Keep the instruction under about 25 words. Longer prompts get partially ignored because the model has to fit them into a fixed runtime.
Six prompt tweaks that work
- Name the audience. “For a new sales hire who has never seen the product.”
- Set a hard angle. “Compare our pricing against the two competitors in the source.”
- Ban a topic. “Do not mention the 2024 pilot, it is outdated.”
- Force numbers. “Include every dollar figure and percentage from the source.”
- Set the ending. “Finish with three action items.”
- Set the tone. “Skeptical, not promotional.”
Combine two or three at most. Four or more and the video starts feeling cramped, because it is trying to satisfy all of them inside the same few minutes.
How many sources should you upload per video?
Five to ten documents is the sweet spot. Below three, the video is thin and repeats itself. Above fifteen, the model spreads attention thinly and the strongest document does not get the screen time it deserves.
Assume one dense source per one to one-and-a-half minutes of video. A 5-minute video comfortably covers 4-6 substantial documents.
Does source order matter?
Yes, more than most people expect. NotebookLM gives early sources more weight in the opening section. Put the document that should frame the whole video first in the source list. If a chart or table is the punchline, upload it as its own source so the model treats it as a first-class item.
When should you regenerate instead of editing?
Regenerating costs you another generation from your daily quota, so it is not free. But there is no sentence-level editor for the narration. If one sentence is wrong, your options are regenerate with a sharper prompt or stop using the video entirely. For anything client-facing, number a single regeneration into your workflow rather than fighting the first output.
Who is this advanced workflow for?
It suits teams publishing internal briefings on a schedule, where a repeatable prompt template saves real time. It is overkill for a one-off summary you will watch once. If you just need the gist of a PDF, the default settings are fine.
Key Takeaways
- A custom generation prompt sets both script and visuals; keep it under about 25 words.
- Five to ten focused sources beat a large dump, and early sources carry more weight.
- Six tweaks — audience, angle, exclusions, numbers, ending, tone — cover most needs.
- Regeneration is the only fix for a bad sentence and it costs a daily generation.
- Worth templating for recurring briefings, overkill for one-off summaries.
