What is an MCP Elicitation?

Without elicitation, a server that lacks a required parameter has only two bad options: guess, or fail outright. Elicitation gives it a third path — it sends a structured request back through the client describing what it needs (a date, a confirmation, a choice among options), and the client renders that as a prompt to the person at the keyboard. The server then resumes with whatever answer comes back, rather than having to encode every possible input path in advance. This matters because most real workflows aren't fully specified upfront. A travel-booking server might not know which of three flight options the user prefers until it asks; a deployment tool might need explicit human confirmation before touching production. Elicitation formalizes that back-and-forth as part of the protocol instead of leaving it to ad hoc chat parsing, which keeps the human clearly in the loop for decisions that matter. The tradeoff is latency and complexity: every elicitation round-trip pauses execution and depends on a responsive human, so well-designed servers reserve it for genuinely ambiguous or high-stakes moments rather than routine parameter-filling.