Having implemented a skill to connect teams to our admin system, we ended up recording it as a Mcp. the Mcp exposes only doc grep and api calls so it's completely useless in itself, but the main reason to go this route was distribution. Non technical teams want a UI where to add a url then everything just works and oauth is guided. Mcp permits that in Claude or chatgpt.
Also the calling of the Mcp is nicer in the chat UI, clearer for users.