Why do we need MCP if skills exist now?

MCP (Modular Capability Protocol) and skills are complementary tools that enhance how agents authenticate and interact with external services. MCP standardizes the interface for authenticated access, resolving issues like bespoke integrations and the need for sharing long-lived API keys, by allowing users to grant scoped access without sharing credentials. Skills, on the other hand, package knowledge in a markdown format that helps agents perform tasks effectively by encoding best practices and tribal knowledge. While MCP has become the standard for third-party integrations despite initial criticisms of security and context bloat, skills have grown popular for their ability to enhance agents' performance by intelligently managing and applying context. The emergence of authenticated CLIs provides a third option that combines the strengths of both MCP and skills, offering standardized patterns and handling authentication naturally. As both MCP and skills continue to mature, they are expected to play crucial roles in AI tooling, providing developers with essential resources for building efficient and effective agents.