What I want to know is what's the difference between a remote mcp and an api with an openapi.json endpoint for self-discovery? It's just as centralized
It's instructive to skim the top level of the MCP spec to get a sense. But you can also scroll to the end of the post and see the three .gifs there and see why MCP: because it also defines interaction models with the clients and exposes MCP prompts as `/` (slash) commands and MCP resources as `@` (at) references among other things.
You are right: MCP tools are in essence OpenAPI specs with some niceties like standardized progress reporting. But MCP is more than tools.
You are right: MCP tools are in essence OpenAPI specs with some niceties like standardized progress reporting. But MCP is more than tools.