Create and Update MR API calls do not support "description" parameter
In the GitLab app you can create a merge request with a description, the Create and Update MR API calls do not support the "description" parameter, please add the "description" parameter tp both Create MR and Update MR API calls.
From the docs:
Create MR Creates a new merge request.
POST /projects/:id/merge_requests Parameters:
id (required) - The ID of a project source_branch (required) - The source branch target_branch (required) - The target branch assignee_id (optional) - Assignee user ID title (required) - Title of MR
Update MR
Updates an existing merge request. You can change branches, title, or even close the MR.
PUT /projects/:id/merge_request/:merge_request_id Parameters:
id (required) - The ID of a project merge_request_id (required) - ID of MR source_branch - The source branch target_branch - The target branch assignee_id - Assignee user ID title - Title of MR