Publish an interface, then advertise it
An MCP server gives an assistant a set of typed tools instead of a website to scrape. Serving a manifest at /.well-known/mcp.json is what makes it findable without someone being told it exists.
Most products that have an API have most of this already. What is missing is the declaration: the machine-readable statement that the interface exists and where it lives.
Check what your robots.txt says about assistants
Rules blocking GPTBot, ClaudeBot, PerplexityBot and their peers are frequently inherited from a template nobody revisited. They are worth an explicit decision rather than a default.
If you want to be cited by assistants, name those crawlers and allow them. If you do not, that is a defensible position, but it should be one you chose.