The Tooling API is great - very easy to use from Apex code by making HTTP calls containing straightforward JSON.
- Is it still not possible to create a new SObject type e.g.
- see Possible to create a new sObject with Tooling API REST interface?
- the CustomObject documentation does not list POST
- Can a custom field be added to an already existing SObject type?
- the CustomField documentation lists POST that makes me think the answer is "yes"