Yes, building free tools related to your product and promote your product inside that tools will be more effective.
This works, but, just so you know, the free tool has to have a minimum of friction to use, and it has to _actually_ be valuable to your audience. Marketing = making others aware that you have a solution for their pain points. These free tools are the simplest expression of that. Deviate from that (complicated set up, low value, etc) and it won't work.
I have been trying to do "marketing as engineer" (not sure where I read the term). In short, let's make cool engineering stuff where you can place your own ads.
For example, I was able to get one of my toy projects at the hn frontpage, I have been speaking at some tech events where I could have mentioned my project.
Related to the product I'm working on, it took me a considerable time but I think I finally figured out a nice strategy to do marketing as engineer (I have high hopes but we'll see how it goes).
Overall, I feel this is considerably more engaging than doing traditional marketing.