feat: add-succes_criteria-to-agent (#3234)

## Summary

Describe key changes, mention related issues or motivation for the
changes.

(If applicable, issue number: #____)

## Type of change

- [ ] Bug fix
- [x] New feature
- [ ] Breaking change
- [ ] Improvement
- [ ] Model update
- [ ] Other:

---

## Checklist

- [ ] Code complies with style guidelines
- [ ] Ran format/validation scripts (`./scripts/format.sh` and
`./scripts/validate.sh`)
- [ ] Self-review completed
- [ ] Documentation updated (comments, docstrings)
- [ ] Examples and guides: Relevant cookbook examples have been included
or updated (if applicable)
- [ ] Tested in clean environment
- [ ] Tests added/updated (if applicable)

---

## Additional Notes

Add any important context (deployment instructions, screenshots,
security considerations, etc.)

Author: Ayush0054

cookbook/agent_concepts/other/success_criteria.py

@@ -0,0 +1,25 @@
+from agno.agent import Agent
+from agno.models.google import Gemini
+from agno.tools.thinking import ThinkingTools
+
+puzzle_master = Agent(
+    model=Gemini(id="gemini-2.0-flash"),
+    tools=[ThinkingTools(add_instructions=True)],
+    instructions="You are a puzzle master for small logic puzzles.",
+    show_tool_calls=False,
+    markdown=False,
+    stream_intermediate_steps=False,
+    success_criteria="The puzzle has been solved correctly with all drinks uniquely assigned.",
+)
+
+
+prompt = """
+Create a small logic puzzle:
+Three friends—Alice, Bob, and Carol—each choose a different drink from tea, coffee, and milk.
+Clues:
+1. Alice does not drink tea.
+2. The person who drinks coffee is not Carol.
+Ask: Who drinks which beverage?
+"""
+
+puzzle_master.print_response(prompt, stream=True, show_reasoning=True)

libs/agno/agno/agent/agent.py

@@ -209,7 +209,7 @@ class Agent:
     # Use these for few-shot learning or to provide additional context to the Model.
     # Note: these are not retained in memory, they are added directly to the messages sent to the model.
     add_messages: Optional[List[Union[Dict, Message]]] = None
-
+    success_criteria: Optional[str] = None
     # --- User message settings ---
     # Provide the user message as a string, list, dict, or function
     # Note: this will ignore the message sent to the run function
@@ -328,6 +328,7 @@ def __init__(
         create_default_system_message: bool = True,
         description: Optional[str] = None,
         goal: Optional[str] = None,
+        success_criteria: Optional[str] = None,
         instructions: Optional[Union[str, List[str], Callable]] = None,
         expected_output: Optional[str] = None,
         additional_context: Optional[str] = None,
@@ -419,6 +420,7 @@ def __init__(
 
         self.description = description
         self.goal = goal
+        self.success_criteria = success_criteria
         self.instructions = instructions
         self.expected_output = expected_output
         self.additional_context = additional_context
@@ -2928,6 +2930,12 @@ def get_system_message(self, session_id: str, user_id: Optional[str] = None) ->
             system_message_content += (
                 f"<transfer_instructions>\n{self.get_transfer_instructions().strip()}\n</transfer_instructions>\n\n"
             )
+        if self.success_criteria:
+            system_message_content += "Your task is successful when the following criteria is met:\n"
+            system_message_content += "<success_criteria>\n"
+            system_message_content += f"{self.success_criteria}\n"
+            system_message_content += "</success_criteria>\n"
+            system_message_content += "Stop running when the success_criteria is met.\n\n"
         # 3.3.10 Then add memories to the system prompt
         if self.memory:
             if isinstance(self.memory, AgentMemory) and self.memory.create_user_memories: