Update index.mdx

docs(concepts): add 'Stateful agents' to concepts section for improved clarity

Author: Jayanth-sanku

docs/docs/concepts/index.mdx

@@ -41,6 +41,8 @@ The conceptual guide does not cover step-by-step instructions or specific implem
 - **[Tracing](/docs/concepts/tracing)**: The process of recording the steps that an application takes to go from input to output. Tracing is essential for debugging and diagnosing issues in complex applications.
 - **[Evaluation](/docs/concepts/evaluation)**: The process of assessing the performance and effectiveness of AI applications. This involves testing the model's responses against a set of predefined criteria or benchmarks to ensure it meets the desired quality standards and fulfills the intended purpose. This process is vital for building reliable applications.
 - **[Testing](/docs/concepts/testing)**: The process of verifying that a component of an integration or application works as expected. Testing is essential for ensuring that the application behaves correctly and that changes to the codebase do not introduce new bugs.
+- **[Stateful agents](/docs/concepts/stateful_agents)**: Agents that maintain memory of previous interactions or state, enabling them to make decisions based on conversation history and context rather than treating each input as independent. This allows for more sophisticated, context-aware behaviors in applications such as chatbots, virtual assistants, and workflow automation.
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 ## Glossary