diff --git a/README.md b/README.md
index c47fa63a..e3d909a9 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,8 @@ from strands import Agent # or bring your agent.
 @app.entrypoint
 async def handler(request):
     prompt = request.get("prompt")
+    if not isinstance(prompt, str):
+        raise ValueError("prompt must be a string")
 
     agent = Agent()
 
@@ -55,6 +57,9 @@ async def handler(request):
 app.run()
 ```
 
+Validate agent input before forwarding it to an agent framework. Keep prompts typed as strings and pass only prompt
+text to the agent.
+
 **What you get with Bedrock AgentCore:**
 - ✅ **Keep your agent logic** - Works with Strands, LangGraph, CrewAI, Autogen, or custom frameworks
 - ✅ **Zero infrastructure management** - No servers, containers, or scaling concerns
diff --git a/src/bedrock_agentcore/runtime/ag_ui.py b/src/bedrock_agentcore/runtime/ag_ui.py
index fac40467..70ea5ab4 100644
--- a/src/bedrock_agentcore/runtime/ag_ui.py
+++ b/src/bedrock_agentcore/runtime/ag_ui.py
@@ -96,6 +96,9 @@ def entrypoint(self, agent_or_func: Any) -> Any:
         - An object with a ``.run()`` method (framework agents)
         - A callable / async generator function (custom agents, decorator form)
 
+        Adapters should validate message content after protocol parsing before forwarding it to another agent
+        framework.
+
         The registered handler is served on both ``POST /invocations`` (SSE)
         and ``/ws`` (WebSocket).
 
diff --git a/src/bedrock_agentcore/runtime/app.py b/src/bedrock_agentcore/runtime/app.py
index f2e596be..870a1a6b 100644
--- a/src/bedrock_agentcore/runtime/app.py
+++ b/src/bedrock_agentcore/runtime/app.py
@@ -215,6 +215,9 @@ def __init__(
     def entrypoint(self, func: Callable) -> Callable:
         """Decorator to register a function as the main entrypoint.
 
+        Invocation payloads are passed to the registered function unchanged. Applications should validate input
+        before forwarding it to an agent framework.
+
         Args:
             func: The function to register as entrypoint
 
diff --git a/tests_integ/agents/streaming_agent.py b/tests_integ/agents/streaming_agent.py
index 33c35005..a4c052c5 100644
--- a/tests_integ/agents/streaming_agent.py
+++ b/tests_integ/agents/streaming_agent.py
@@ -12,6 +12,8 @@ async def agent_invocation(payload):
     user_message = payload.get(
         "prompt", "No prompt found in input, please guide customer to create a json payload with prompt key"
     )
+    if not isinstance(user_message, str):
+        raise ValueError("prompt must be a string")
     stream = agent.stream_async(user_message)
     async for event in stream:
         app.logger.info("Streaming event: %s", event)
diff --git a/tests_integ/async/interactive_async_strands.py b/tests_integ/async/interactive_async_strands.py
index 43025ae1..62f658dc 100644
--- a/tests_integ/async/interactive_async_strands.py
+++ b/tests_integ/async/interactive_async_strands.py
@@ -517,6 +517,8 @@ def agent_invocation(payload):
         "Hello! I can start long-running data processing tasks. Try: "
         "'Start processing a large dataset for ML training' or 'What are my options?'",
     )
+    if not isinstance(user_message, str):
+        raise ValueError("prompt must be a string")
 
     result = agent(user_message)
 
diff --git a/tests_integ/runtime/test_simple_agent.py b/tests_integ/runtime/test_simple_agent.py
index 65d24f56..53a383f1 100644
--- a/tests_integ/runtime/test_simple_agent.py
+++ b/tests_integ/runtime/test_simple_agent.py
@@ -20,7 +20,10 @@ def setup(self):
 
                 @app.entrypoint
                 async def agent_invocation(payload):
-                    return agent(payload.get("message"))
+                    message = payload.get("message")
+                    if not isinstance(message, str):
+                        raise ValueError("message must be a string")
+                    return agent(message)
 
                 app.run()
             """).strip()