Quoting Sean Lynch
MCP's core value is isolating API auth flows outside the agent's context window, not tool definitions.
“Maybe the idealized form of MCP is just an auth gateway for the API and nothing else. That'd still be a win.”
Sean Lynch argues in a Hacker News comment, surfaced by Simon Willison, that MCP's most valuable distinction over skills or CLI tools is keeping authentication flows out of the agent's context window. It reframes MCP as primarily an auth gateway rather than a tool-definition layer, a notable architectural take amid ongoing debate over MCP's role versus agent skills.