The documentation for Tooling API suggests that Tooling API supports composite/sobjects resource
Update Multiple Records with Fewer Round-Trips Use a PATCH request with sObject Collections to update multiple records, returning a list of SaveResult objects. You can choose whether to roll back the entire request when an error occurs.
However, looks like in fact, this resource is not supported, since any PATCH calls to this resource return
Service not found at: /services/data/v56.0/tooling/composite/sobjects
error.
Also, the link to the API resource in documentation is also wrong:
PATCH /vXX.X/composite/sobjects
while in fact, for tooling api, it is /v56.0tooling/composite/sobjects
.
If usual REST API resource is used, another error is returned "SObject is not supported".
Is there are workaround other than using Metadata API to bulk update custom fields, custom objects and other Tooling API objects?