When using Toad to generate create script for a synonym that refers to an object across a dblink, Toad includes schema name in the for section which causes ORA errors.
CREATE SYNONYM "schema"."object" FOR "schema"."object"@dblink
CREATE SYNONYM "schema"."object" FOR "object"@dblink
Manually remove the schema name generated from the script.
Waiting for fix in future release of Toad for Oracle.