MCP vs. CLI: When to Use Them and Why
Blog post from Descope
In March 2026, Perplexity's CTO Deni Yarats announced a shift from MCP (Message Control Protocol) to traditional APIs and CLIs (Command-Line Interfaces) within the company, sparking a debate over the merits of each approach. The discussion revealed divided opinions, with some favoring CLIs for their token efficiency and familiarity with shell interactions, while others supported MCP for its architectural advantages in managing user authentication, consent, and audit trails. While CLIs are advantageous for individual developers due to their simplicity and lower token usage, MCP is seen as more suitable for environments requiring robust security and multi-tenancy due to its structured support for authentication and authorization protocols. The debate underscores the importance of choosing the right tool based on the agent's role, with a hybrid approach often being recommended: using CLIs for local development and MCP for interacting with remote services and handling complex security requirements. Ultimately, the underlying challenge of identity management remains a critical factor, with solutions like Descope offering tools to streamline OAuth compliance, user consent, and credential management for AI agents.