Action Step: Update your assistant's system prompt to explicitly instruct it to use the query tool by name. For example, add this to your system prompt:

When users ask about products, pricing, features, or need troubleshooting help, use the 'knowledge-search' tool to search our knowledge base for accurate information. Always call the knowledge-search tool before providing answers to ensure accuracy.

This step is critical—without it, the assistant may not trigger the query tool even if everything else is configured correctly. For more details, see the [official guide](https://docs.vapi.ai/knowledge-base/using-query-tool). Source: - [Using the Query Tool for Knowledge Bases](https://docs.vapi.ai/knowledge-base/using-query-tool)

The issue is still even when the query tool ran this is what assistant said: The unexpected error you're seeing is related to receiving data that's not in the expected JSON format. Instead of valid JSON, it's receiving HTML data starting with bars, which usually occurs when the server sends back a web page instead of the expected structured data. This might be due to configuration issues, network problems, or incorrect endpoint handling on the server side.

Hey, This has been resolved. The knowledge base issues were caused by Google Gemini rate limiting on their infrastructure. Status: Fixed as of Jan 21, 11:30pm PST. Try your knowledge base again - it should be working now. If you still have issues, let me know with a call ID and I can dig deeper. Incident details: https://status.vapi.ai/incident/809181