Query tool calls ignore required query param + assistant overrides confusing tool schema Hi Vapi Support , we’re troubleshooting a query tool used for searching listings and the agent is being inconsistent in finding any listings, we had this agent setup for over 7+ month now and didn't make any changes related to these, it just started happening. Call ID: 019e51be-235d-7cc0-8ded-73523a374df4 and second one 019e51c5-27cd-7999-b546-2237c6e3772a

Hi, thanks for sharing the call IDs, I investigated both calls and found the root cause. The issue is that your

Astra_leasing_prototype

query tool schema only defines

knowledgeBaseNames

and does not explicitly define a required

query

parameter. Because of that, the assistant sometimes sends tool calls without the actual search text, which causes the knowledge base search to return

"No answer found in the knowledge base"

. Example of the tool call currently being sent:

{
  "name": "Astra_leasing_prototype",
  "arguments": {
    "knowledgeBaseNames": [
      "Astra_listings_update"
    ]
  }
}

Since no query string is included, the KB has nothing to search against. To fix this, please update the tool parameter schema and add

query

as a required string field:

{
  "type": "object",
  "properties": {
    "knowledgeBaseNames": {
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "Astra_listings_update",
          "Astra_Genenral_KB"
        ]
      },
      "minItems": 1
    },
    "query": {
      "type": "string",
      "description": "The search query in plain english, e.g. 'one bedroom apartment in Racine under $1200'"
    }
  },
  "required": [
    "knowledgeBaseNames",
    "query"
  ]
}

Also: • Verify the

Astra_listings_update

knowledge base still contains valid/up-to-date indexed content • Add explicit prompt instructions telling the assistant it must always include the

query

argument when calling the tool After updating, test another call and verify in the dashboard → Calls → Tool Calls that both: •

knowledgeBaseNames

•

query

are present in the tool arguments.