Subject: Tool input_schema arrives empty to the model despite being correctly configured - blocking functionality in production

Body:

Assistant ID: 86c82e9c-f8c2-45be-8522-55b6d2886bc9

The 4 tools in this assistant have their Request Body schema correctly configured and saved (confirmed via API — function.parameters with properties, required, and additionalProperties: false):

query_tracking (a2b23afd-8fa6-471b-8dc0-247aa453fc90) — reference parameter

quote_shipment (f2933d6a-3147-4d66-b72a-b24097ac0203) — 8 parameters

request_pickup (0a624a13-e32d-4906-a19e-54cb21969464) — 7 parameters

search_customer (2685819b-793a-4c03-924d-965c293fcce9) — telephone parameter

However, in EVERY real test call (example CallID: 019f37fc-46d2-7000-83d5-518c74e506e1), log assistant.model.requestAttemptStarted shows that the actual request sent to the model (Anthropic Claude Sonnet 4.6) contains these tools with:

“input_schema”: {“type”: “object”, “properties”: {}}

Completely empty, and with generic names (APIRequest-xxxxxxxx) instead of real names.

As a result, the model calls the tools without any parameters, and our backend receives requests without the required field, returning error 400.

We have already tried: re-save each tool individually, re-save the entire assistant, and publish (Publish) — the problem persists in an identical way.

Can you confirm if there is a synchronization/cache problem between the saved schema (function.parameters) and the one that is actually transmitted at runtime to the model provider? This is blocking the full functionality of our assistant in production.