Merge pull request modelcontextprotocol#197 from modelcontextprotocol/jerome/feature/progress-update-message

Added optional message field to progress notifications

Author: dsp-ant

docs/specification/draft/basic/utilities/progress.md

@@ -36,6 +36,7 @@ The receiver **MAY** then send progress notifications containing:
 - The original progress token
 - The current progress value so far
 - An optional "total" value
+- An optional "message" value
 
 ```json
 {
@@ -44,14 +45,16 @@ The receiver **MAY** then send progress notifications containing:
   "params": {
     "progressToken": "abc123",
     "progress": 50,
-    "total": 100
+    "total": 100,
+    "message": "Reticulating splines..."
   }
 }
 ```
 
 - The `progress` value **MUST** increase with each notification, even if the total is
   unknown.
 - The `progress` and the `total` values **MAY** be floating point.
+- The `message` field **SHOULD** provide relevant human readable progress information.
 
 ## Behavior Requirements
 

schema/draft/schema.json

@@ -1284,6 +1284,10 @@
                 },
                 "params": {
                     "properties": {
+                        "message": {
+                            "description": "An optional message describing the current progress.",
+                            "type": "string"
+                        },
                         "progress": {
                             "description": "The progress thus far. This should increase every time progress is made, even if the total is unknown.",
                             "type": "number"

schema/draft/schema.ts

@@ -289,6 +289,10 @@ export interface ProgressNotification extends Notification {
      * @TJS-type number
      */
     total?: number;
+    /**
+     * An optional message describing the current progress.
+     */
+    message?: string;
   };
 }