> What other alternatives exist in place of MCP? Arbitrary code via curl/sdks to call a remote endpoint?

cli?

for example aws cli. It's a full interface to aws API. Why would you need mcp for that?

and if you have any doubts, agents use it with a great effect even without any relevant skill. "aws help" is fully discoverable.

yes, but clis thus need self-service commands to provide guidance, and their responses need to be optimized for consumption by agents. in a sense, this is the same sort of context tax that MCP servers incur. so in my view cli and MCP are complementary tools; one is not strictly superior over the other.