What is MCP?

MCP is an acronym for a way to represent a service for LLMs, as noted by Bill Gurley in Apr 2025. As of Mar 2026, Karan Vaidya observed that providing 1,000 MCPs to an LLM can hit 1 million context windows, adding that “attention is definitely not free.” Walden Yan noted in May 2026 that achieving proper integration and the right experience often required building custom, ad hoc solutions.