Comment by crooked-v

Having built out MCP functionality for actual use cases for a small company, the big gotchas for us that can't be handled with "just an API" (putting aside the auth flow thing) have so far been (a) fully custom UI pieces in GUI clients (for example, media embeds with custom rendering) and (b) having the ability to put a user-facing hard stop in the loop for some interactions.

Part (a) in particular is pretty prominent for us since our uses cases are all about video, and having "just" an iframe URL to supply, with no other interaction with the model/turns, would give a pretty janky and unpleasant experience if Claude/ChatGPT even allowed it to embed.