> MCP promises to standardize AI-tool interactions as the “USB-C for AI.”
Ironically, it's achieved this - but that's an indictment of USB-C, not an accomplishment of MCP. Just like USB-C, MCP is a nigh-universal connector with very poorly enforced standards for what actually goes across it. MCP's inconsistent JSON parsing and lack of protocol standardization is closely analogous to USB-C's proliferation of cable types (https://en.wikipedia.org/wiki/USB-C#Cable_types); the superficial interoperability is a very leaky abstraction over a much more complicated reality, which IMO is worse than just having explicitly different APIs/protocols.
I'd like to add that the culmination of USB-C failure was Apple's removal of USB-A ports from the latest M4 Mac mini, where an identical port on the exact same device, now has vastly different capabilities, opaque to the final user of the system months past the initial hype on the release date.
Previously, you could reasonably expect a USB-C on a desktop/laptop of an Apple Silicon device, to be USB4 40Gbps Thunderbolt, capable of anything and everything you may want to use it for.
Now, some of them are USB3 10Gbps. Which ones? Gotta look at the specs or tiny icons, I guess?
Apple could have chosen to have the self-documenting USB-A ports to signify the 10Gbps limitation of some of these ports (conveniently, USB-A is limited to exactly 10Gbps, making it perfect for the use-case of having a few extra "low-speed" ports at very little manufacturing cost), but instead, they've decided to further dilute the USB-C brand. Pure innovation!
With the end user likely still having to use a USB-C to USB-A adapters anyways, because the majority of thumb drives, keyboards and mice, still require a USB-A port — even the USB-C ones that use USB-C on the kb/mice itself. (But, of course, that's all irrelevant because you can always spend 2x+ as much for a USB-C version of any of these devices, and the fact that the USB-C variants are less common or inferior to USB-A, is of course irrelevant when hype and fanaticism are more important than utility and usability.)
As far as I know, please correct me if I'm wrong, the USB spec does not allow USB-C to C cables at all. The host side must always be type A. This avoids issues like your cellphone power supplying not just your headphones but also your laptop.
No, you're thinking about USB-A to USB-A, which is definitely prohibited by the spec. (Whereas USB-C to USB-C cables are most certainly not disallowed.)
What's disallowed is for a non-host to have USB-A, hence, USB-A to USB-A is impossible, because one side of the cable has to be connected to a "device" that's not acting in host mode.
Only the host is allowed to have USB-A.
This is exactly why USB-A is superior to USB-C for host-only ports on embedded devices like routers (as well as auxiliary USB ports on your desktop or monitor).
Generally, many modern travel routers have one USB-C and one USB-A port. Without any documentation or pictograms, you can be relatively sure that USB-A would be used for data, and USB-C is for power (hopefully, through USB-PD). Since USB-A couldn't possibly be used to power up the router, since USB-A is a host-only port.
USB-C is great for USB-OTG and the bidirectional modes, when the same port could be used for both the host and the peripheral device functions, like on the smartphones. https://en.wikipedia.org/wiki/USB_On-The-Go
If the port can ONLY be used in host-mode, and does NOT support Alt Mode, Thunderbolt, or bidirectional USB-PD, then USB-A is a far more fitting connector, to signify all of the above.
Ironically, it's achieved this - but that's an indictment of USB-C, not an accomplishment of MCP. Just like USB-C, MCP is a nigh-universal connector with very poorly enforced standards for what actually goes across it. MCP's inconsistent JSON parsing and lack of protocol standardization is closely analogous to USB-C's proliferation of cable types (https://en.wikipedia.org/wiki/USB-C#Cable_types); the superficial interoperability is a very leaky abstraction over a much more complicated reality, which IMO is worse than just having explicitly different APIs/protocols.