What are the best software design strategies and tools to communicate a concept to developers?

As background, I have a mechanical engineering background but am not a software engineer or programmer. I am good with project management but lack meaningful depth of knowledge related to software architecture and design. That being said, I’m in the process of developing a piece of software for the medical space. Prior to approaching developers, my hope is to have this idea as best as possible sketched out to translate the concept in a clear fashion. I have a limited budget so anything I can do to reduce the amount of extra unnecessary development costs is worthwhile leg work.

To this point, the following has been done:

• wire-framed the front end UI flow
• roughed out the logic for an financial optimization process
• drawn out a conceptual and contextual level ERD
• created user stories/narratives for the various groups of software end users

My question is, what else can I do / should I consider doing to flush out this concept so that the developers have clear parameters for understanding the project scope and therefore most accurately quote on the build-out cost and development time?

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TIA-