.Net: Fixing ConversationSummaryPlugin's ActionItems response by impr…

…oving underlying prompt (#6722)

Fixing ConversationSummaryPlugin's ActionItems response by improving
underlying prompt

### Motivation and Context

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  1. Why is this change required?
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1. Why is this change required?
This change is required in order to fix reported [issue:
4843](#4843)
The change improves the prompt behind the "GetConversationActionItems"
function of "ConversationSummaryPlugin", in order to get
expected/correct results.

2. What problem does it solve?
The "GetConversationActionItems" doesn't return expected result. It even
did not return as expected by the MS Learning path samples. Upon
checking the issues, I found [Issue
4843](#4843) already
opened against it, so I tried to find the root cause of this behavior
and fix it.

### Description

The change improves the prompt behind the "GetConversationActionItems"
function of "ConversationSummaryPlugin", in order to get
expected/correct results.

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

dotnet/src/Plugins/Plugins.Core/PromptFunctionConstants.cs

@@ -19,10 +19,14 @@ internal static class PromptFunctionConstants
 
     internal const string GetConversationActionItemsDefinition =
         """
-        You are an action item extractor. You will be given chat history and need to make note of action items mentioned in the chat.
+        You are an action item extractor. You will be given chat history or content and need to make note of action items mentioned.
         Extract action items from the content if there are any. If there are no action, return nothing. If a single field is missing, use an empty string.
         Return the action items in json.
 
+        Guidelines:
+        Action items are specific tasks or requests that someone needs to complete.
+        Routine statements or general comments about habits or preferences should not be considered action items.
+
         Possible statuses for action items are: Open, Closed, In Progress.
 
         EXAMPLE INPUT WITH ACTION ITEMS:
@@ -43,6 +47,23 @@ internal static class PromptFunctionConstants
             ]
         }
 
+        EXAMPLE INPUT WITH IMPLIED ACTION ITEMS:
+
+        I need a list of vegan breakfast recipes. Can you get that for me?
+
+        EXAMPLE OUTPUT:
+        {
+            "actionItems": [
+              {
+                  "owner": "",
+                  "actionItem": "Give a list of breakfast recipes that are vegan friendly",
+                  "dueDate": "",
+                  "status": "Open",
+                  "notes": ""
+              }
+            ]
+        }
+
         EXAMPLE INPUT WITHOUT ACTION ITEMS:
 
         John Doe said: "Hey I'm going to the store, do you need anything?"