How do I resolve the 'Non string tool message content is not supported' error when retrieving contacts from Qdrant in n8n?

Below is the output returned by your last node:

JSONCopied
[
    {
        "response": [
            {
                "type": "text",
                "text": "{\"pageContent\":\"name,email_address: Sara Smith ,sara.smith@gmail.com\"}"
            }
        ]
    }
]

---

Explanation & Suggestions

The error message:

  "Non string tool message content is not supported"

indicates that the agent expects a plain string as tool message content, but it’s receiving a JSON-encoded string instead. In your output the text received is:

  "{"pageContent":"name,email_address: Sara Smith ,sara.smith@gmail.com"}"

This means the content is wrapped as JSON instead of being a straightforward text string.

To resolve this:

1. Parse the JSON output:
   Add a function (or similar node) to parse the JSON string and extract the actual text value (e.g. the value of pageContent).

2. Convert the output to a plain string:
   Once parsed, ensure only the simple string (e.g.
   "name,email_address: Sara Smith ,sara.smith@gmail.com") is forwarded to the agent/tool as the message content.

3. Double-check node configuration:
   Verify that the node returning the tool output isn’t inadvertently wrapping the output in an extra JSON structure. Adjust the formatting (or use an expression) as necessary so that the final output is a plain string.

These changes should help prevent the “Non string tool message content is not supported” error when retrieving contacts from your database.