diff --git a/packages/components/src/agents.ts b/packages/components/src/agents.ts
index e30a0c43a..5e241d505 100644
--- a/packages/components/src/agents.ts
+++ b/packages/components/src/agents.ts
@@ -606,9 +606,18 @@ class ExceptionTool extends Tool {
 
 export const formatAgentSteps = (steps: AgentStep[]): BaseMessage[] =>
     steps.flatMap(({ action, observation }) => {
+        const create_function_message = (observation: string, action: AgentAction) => {
+            let content: string
+            if (typeof observation !== 'string') {
+                content = JSON.stringify(observation)
+            } else {
+                content = observation
+            }
+            return new FunctionMessage(content, action.tool)
+        }
         if ('messageLog' in action && action.messageLog !== undefined) {
             const log = action.messageLog as BaseMessage[]
-            return log.concat(new FunctionMessage(observation, action.tool))
+            return log.concat(create_function_message(observation, action))
         } else {
             return [new AIMessage(action.log)]
         }