A long-running report tool sends progress notifications, and users want to see readable status such as "Parsing page 40 of 120" instead of just a bar. Which part of the progress notification carries this text?
Select an answer to reveal the explanation.
Short Explanation
The progress bar is the numbers; the caption underneath is the message field. You keep the token fixed, let progress climb, and drop your friendly status text into message. That's what it's there for.
Full Explanation
The progress pattern lets a client opt in by putting a progressToken in the request's _meta. The server MAY then send notifications/progress carrying the original token, the current progress value, an optional total and an optional message, and the specification says the message field SHOULD provide relevant human-readable progress information. The progress value MUST increase with each notification even when the total is unknown, and both values may be floating point. The progressToken identifies which request the notification belongs to, must be a string or integer chosen by the client, and must be unique across active requests, so a server cannot rewrite it without breaking correlation. total is an optional number used to compute a percentage; it is simply omitted when unknown rather than turned into text. resultType appears on results, not notifications, and input_required means the server needs input from the client before it can finish, through the multi round-trip mechanism, not that work is ongoing. Exam caveat: progress notifications must stop after the request completes, and both parties SHOULD rate limit them to avoid flooding. Operational check: call the tool with a progressToken and confirm each notification carries the same token, an increasing progress value and a readable message the host displays.