Do you know tools (not methods) in the form of a guide to help in designing and maturing products? Something that prepares the idea for the formation of a product on your MVP1?
Unless I'm mis-understanding your question...this is the basis of "product development". I suggest search for, "tools for product development".
Many are methods used to to take an idea from initial concept through deliverable products. - And recently they have been offered for sale as software packages.
They are also named, tools for "Product Strategy and Road-mapping**"
One that's free is the concept, "Eight Stage Gate Process for New Product Development" developed by Robert G. Cooper.
Other tools are grouped into the following areas: (sorry for the obtuse titles but these names are representative of current tools)
Product strategy and roadmapping**
Analytics
Customer feedback and surveys
Design and wireframing
User experience testing
User onboarding
Collaboration and productivity
Project and task management
I doubt the separating method vs tool is conducive to research . In my experience we use a design methodology (method) process for carrying out research. Analytical tools are one part of looking at an potential of an idea.