Historically toolsdb has been utilized primiarly within Toolforge, and while much newer, Trove has been only utilized within cloud VPS projects. Given the success of using trove within toolforge T323502, and similar precedence of cloud vps projects relying on toolsdb (often after migrating from toolforge), let's update the documentation accordingly.
Rather than be seen as platform specific DbaaS, instead update messaging to convey (feel free to correct / suggest):
Toolsdb
* For simpler / less complex applications
* Strict connection limits (currently 20 per user, 1024 tool)
* Strict database size limits (no current quota, likely less than 1G per tool; but practical limits exist -- see {T301949} and {T329970})
* Being shared, not suitable for high-performance
* Allows databases to be easily shared across projects (read)
* No administration responsibilities required for users
Trove
* For more complex / more demanding applications
* Suitable for higher performance needs
* Project controlled access and connection limits
* Requires small amount of administration responsibilities
* Databases specific to each project and not shared