Right now the SOQL Query tool window works against the metadata API. A few folks have asked for query support against tooling API SObjects. To do this right, the tooling API SObjects should also be included in the OST so that they're available for code completion. To do this really right, the SObjects that are exclusive to the tooling API should only be available for code completion in the SOQL Query tool window when it's configured to use the tooling API.
Issue #373 new