This appears to be a documentation inconsistency. The CLI implementation seems to:

  1. Require binding_type to be explicitly specified (contradicting the docs)

  2. Require it to be placed within each workspace object, not as a top-level parameter

 The fact that removing bindings works suggests the CLI can parse the structure correctly for remove operations but has stricter  requirements for add operations.

  Additional Verification Steps

  Could you share:

  1. Are you using numeric workspace_id or string? Try ensuring it's numeric without quotes

  2. Which version of the Databricks CLI are you using? 

This would help confirm if it's a CLI version-specific issue or a persistent bug in the workspace bindings implementation.