Tool loops are the new feedback loop. The reason SaaS was priced so lucratively in the 2000s was because of the feedback loop created by software. Feedback loops drive quick iteration which in turn ultimately reduces risk and drives up the value of ideas. The faster you can iterate, the more ideas you can test which gives you more lottery tickets to buy.
The inverse is hopefully obvious. Hardware and biology receive lower valuations because the cost of wet lab and hardware mistakes are incredibly costly which in turn increases the need for capital and thus more risk.
Tool loops are in my opinion the new manifestation of the feedback loop. It's safe to say that no other field has been so dramatically impacted other than engineering right now. This impact is entirely driven by the tool loop. The ability for a model to correctly take in an error log, read the code, query the DB, search Slack for other, potentially resolved issues and then finally write a fix for the error. All while an engineer grabs coffee.
That loop. That loop can be parallelized at a mind bogglingly massive scale.
The MCP believers, to their credit, saw this possibility. What if we could turn the web into a collection of tools with infinite combination. Suddenly you could create tool loops for any industry. Unfortunately, due to limitations of models at the time, combining multiple together really hampered models.
That magic though, when it happens, completely blows you away. It's a glimpse into the next room, a room we've never seen before.