To access feature type parameters, click the gear icon 
on a feature type in the workspace to open the Feature Type Parameter Editor. To always display the editor in Workbench, you can select View > Windows > Parameter Editor.
General
All feature types share similar General parameters, including the Feature Type Name, Reader or Writer Name, and Geometry.
In most Writer Feature Type parameter dialogs, you can also control Dynamic Schema Definitions. Some database formats accept a Table Qualifier prefix on the output table feature type.
See Editing Writer Feature Types for more information.
These parameters apply only to a selected feature type, not to the entire writer.
Tip: If a feature type parameter listed here conflicts with a writer-level parameter, then the writer parameter will be ignored and this feature type parameter will be used.
Collection
JSON Query
This parameter specifies a JSON document that will be used to filter input features. The JSON document should be formatted as if calling the method db.collection.find() in the MongoDB shell. See the MongoDB documentation.
Example
To filter features where the attribute foo has the value bar, the JSON Query should be:
{ “foo”: “bar” }