Google Flow is already known as a powerful platform for creating AI-generated videos, characters and creative assets. However, one of its most useful features often goes unnoticed: the ability to build your own customized AI tool.
You do not need coding knowledge, an expensive setup or a team of developers. All you need is a clear idea of what you want the tool to do. Google Flow can then turn that idea into a functional tool within minutes.
In this guide, we will explore how this hidden feature works by creating a custom tool that generates UGC-style product advertisement videos.
What Is the Custom Tool Builder in Google Flow?
The custom tool builder allows you to create a specialized workflow for a particular task. Instead of repeatedly entering detailed prompts whenever you want to generate something, you can design a tool with predefined options and instructions.
For example, you could build tools for:
- UGC advertisement videos
- Product showcase videos
- Social media creatives
- Promotional video concepts
- Character-based content
- Music-video ideas
- Product photography concepts
Once your tool is ready, you can upload an asset, choose the required settings and generate content through a much simpler workflow.
Why Is This Feature Useful?
Most general AI tools require users to write a new prompt for every project. The result often depends on how clearly and consistently the prompt is written. A custom tool solves this problem by turning your preferred process into a reusable system.
This feature can help you:
- Save time on repetitive prompting
- Maintain a consistent workflow
- Create tools for a specific content niche
- Give users clear options before generation
- Reduce wasted credits caused by unwanted results
- Modify and improve a tool without rebuilding it from scratch
It is especially helpful for creators, digital marketers, small businesses and agencies that regularly produce similar types of content.
How to Create Your Own Tool in Google Flow
Step 1: Open a New Project
Open Google Flow on your mobile device or computer and select New Project. Once the workspace opens, go to the Tools section.
Here, you should find three main categories:
- My Tools – Tools you have created or customized
- Community – Tools shared by other users
- Templates – Ready-made tools for common creative tasks
To create something from scratch, open My Tools and select Create New.
Step 2: Describe Your Tool in Simple Language
You will now need to explain what you want the tool to do. There is no need to write code or use complicated technical language. A clear, detailed description is enough.
For a UGC video tool, your instruction could look like this:
Create a tool that produces UGC-style advertisement videos. The user will upload a product image. The tool should analyze the product and suggest three suitable video concepts, such as a product beauty shot, a model using the product or a model speaking about its benefits. Before generating the video, allow the user to select the aspect ratio, video duration, model appearance and location.
The more clearly you define the workflow, the better the generated tool will match your requirements.
Important Options to Add to a UGC Video Tool
A good custom tool should not immediately generate a video after a product is uploaded. It should first collect the user’s preferences. This avoids unnecessary generations and helps protect available credits.
Useful options include:
Aspect Ratio
Allow users to choose a format based on the target platform, such as vertical for Reels and Shorts or landscape for YouTube.
Video Duration
Let the user choose the desired duration within the generation limits supported by Google Flow.
Model Appearance
Provide choices for relevant visual details such as overall appearance, hairstyle, expression, clothing or presentation style.
Environment or Location
Allow the user to choose where the advertisement takes place—for example, a studio, kitchen, bedroom, outdoor location or luxury interior.
Product Image Upload
Include a media-upload section so the tool can analyze the actual product before suggesting video concepts.
Multiple Concept Suggestions
Ask the tool to provide three relevant video ideas after examining the uploaded product. The user can then select a concept before spending credits on video generation.
Generating a UGC Advertisement Video
After the tool has been created, upload a clear image of your product. Google Flow will analyze the image and produce video suggestions based on the instructions built into your tool.
For example, if you upload a chocolate product, it may suggest concepts such as:
- A lifestyle scene in which the model takes a short break and enjoys the chocolate
- A polished product-reveal video with close-up shots
- A UGC testimonial in which the model introduces and tries the product
Select the idea that best matches your campaign, choose the remaining settings and click the video-generation option. Once processing is complete, review the result and export it to your device.
How to Edit and Improve Your Tool
One of the best parts of this feature is that your first version does not have to be perfect. You can continue improving the tool by typing new instructions.
Suppose your tool offers three ideas but none of them suits the user. You can add an instruction such as:
Add a “New Ideas” or “Retry” button that analyzes the product again and provides three different video suggestions.
After submitting the instruction, Google Flow updates the tool. You can upload the product again, review the suggestions and request new concepts whenever necessary.
You can use the same approach to add or refine fields, change the workflow and improve the generated output.
Can You Customize Community Tools and Templates?
Yes. You can modify a tool from the Community or Templates section to match your requirements. Your changes are saved as a separate version under My Tools, while the original public tool remains unchanged.
This is useful when an existing tool is close to what you need but lacks a particular option or workflow step.
Where Are Generated Videos and Images Saved?
Assets created inside Google Flow are generally available in the project’s media area. If you forget to download an image or video before starting another generation, check All Media to find previously generated assets.
It is still a good practice to export important files and organize them locally as soon as the final result is approved.
Important Limitation to Remember
Custom tools must operate within the generation rules and technical limits available in Google Flow. Creating your own tool does not remove the platform’s existing restrictions.
For example, if the supported video-generation duration is between 3 and 10 seconds in the selected workflow, adding a 20-second or 30-second option to your custom interface will not force the system to produce a longer clip.
Available credits, plan benefits, generation limits and promotional offers may also change over time. Always check the latest information displayed in your own account before planning a large project.
Tips for Building a Better Custom AI Tool
- Start with one clear purpose instead of trying to make one tool do everything.
- Describe the user’s journey from upload to final output.
- Add selection options before the generation step.
- Ask for multiple concepts so users can choose the best direction.
- Include a retry option for fresh suggestions.
- Use clear labels that are easy for beginners to understand.
- Test the tool with different products before relying on it for client work.
- Refine the instructions whenever you notice repeated output problems.
Final Thoughts
Google Flow’s custom tool builder can turn a simple idea into a reusable AI workflow without traditional coding. In only a few steps, you can create a specialized tool, upload a product, receive relevant concepts, generate a video and refine the process according to your needs.
For creators and marketers, the real benefit is not just faster content generation. It is the ability to build a repeatable production system tailored to a specific niche.
If you regularly create UGC advertisements, product videos or social media content, this feature is worth exploring. Begin with a simple use case, test the results and keep improving your tool as your workflow develops.
