The tool specified is not licensed. Whenever a tool is executed in a script, an ArcGIS Desktop license is required. Tools from ArcGIS extensions, such as ArcGIS ArcGIS Spatial Analyst, require an additional license for that extension. If the necessary licenses are not available, a tool will fail and return appropriate error messages.
When using an ArcGIS Desktop Basic or ArcGIS Desktop Standard license, a script should set the product to ArcGIS Desktop Basic or ArcGIS Desktop Standard. Likewise, when using an ArcGIS Engine or EngineGeoDB license, a script should set the product to Engine or EngineGeoDB. If a license is not explicitly set, the first time ArcPy is used, the license will be initialized based on the highest available license level. Learn more about access to licensing and extensions.