This is the third post in a series about making my site's search available to AI agents. First, I published an API Catalog, which helps agents that already know to check my site find its search API. Second, I added an Agentic Resource Discovery (ARD) entry so my search can be indexed by "AI registries" (think search engines for AI agents). Until last week, I had decided Model Context Protocol (MCP) was not worth implementing for my search API endpoint. OpenAPI and MCP handle invocation by defining how agents can call and use those services.