{
  "lesson": "13-prompts-and-completion",
  "title": "Prompt Templates and Argument Completion",
  "questions": [
    {
      "stage": "pre",
      "question": "In MCP 2026-07-28, who decides when a particular prompt is invoked?",
      "options": [
        "The user selects it explicitly, since prompts are designed to be user controlled",
        "The model selects it automatically whenever the conversation needs more context",
        "The server schedules it automatically on a fixed recurring time interval",
        "The host renders it without asking the user or the model at all"
      ],
      "correct": 0,
      "explanation": "Prompts are user-controlled: a server authors their content, but the user is the one who explicitly selects when a prompt runs, often through a menu or slash command."
    },
    {
      "stage": "check",
      "question": "A client calls prompts/get for a prompt with one required argument and supplies no arguments at all. What does a conformant server return?",
      "options": [
        "A JSON-RPC error with code -32601 because the prompt itself is missing",
        "A JSON-RPC error with code -32602 because a required argument is missing",
        "An input_required result that asks the model to supply the value",
        "A normal result whose messages array is simply left completely empty"
      ],
      "correct": 1,
      "explanation": "Missing a required prompt argument is a JSON-RPC error with code -32602 Invalid params; -32601 is reserved for a method the server does not implement at all."
    },
    {
      "stage": "check",
      "question": "A completion/complete request matches 137 possible values for one argument. How many does the result's values array contain, and what else must it report?",
      "options": [
        "Zero values, because completion refuses requests above 100 possible matches",
        "All 137 values plus a total field and hasMore set to false",
        "At most 100 values, with hasMore true since more matches exist",
        "Exactly 10 values by default, with pagination handled by a cursor"
      ],
      "correct": 2,
      "explanation": "A completion result never carries more than 100 ranked values; when more matches exist than that cap, the result also sets hasMore to true so the client knows the list was cut short."
    },
    {
      "stage": "check",
      "question": "A client is completing a prompt's second argument and has already resolved the first one. How should it help the server narrow the suggestions?",
      "options": [
        "Repeat the first argument inside the value field of the one being completed",
        "Send a separate tools/call first so the server remembers the earlier answer",
        "Open a subscriptions/listen stream and publish the earlier answer onto it",
        "Carry the earlier answer in context.arguments on the completion request"
      ],
      "correct": 3,
      "explanation": "completion/complete accepts a context.arguments map of already-resolved argument names to values, which lets the server narrow suggestions for the argument currently being typed."
    },
    {
      "stage": "post",
      "question": "A prompt message needs to point at a large reference file without inlining its bytes into the message. Which content type fits that job?",
      "options": [
        "A resource_link block with the file's uri, a name, and its mime type",
        "An audio block, since resource references are only valid for sound content",
        "A text block that copies the entire file inline as one long block of text",
        "An image block, since resource references are only valid for picture content"
      ],
      "correct": 0,
      "explanation": "A resource_link content block lets a prompt message point at a resource by uri, name, and mime type without embedding the resource's full contents in the message."
    },
    {
      "stage": "post",
      "question": "A client sends prompts/list with a cursor value the server never issued. What should a conformant server do with that request?",
      "options": [
        "Silently ignore the bad cursor and return the very first page again",
        "Reject the request with a JSON-RPC error, code -32602 invalid params",
        "Treat the cursor as valid and return an empty prompts array only",
        "Start an entirely new connection and replay the whole prompt catalog"
      ],
      "correct": 1,
      "explanation": "Cursors are opaque tokens the server itself issues; a cursor the server does not recognize is an invalid parameter and must be rejected with error code -32602."
    }
  ]
}