When localization is turned on within a site, there are additional prompts at the top of the report editors:
Localizing a Report Description
The Localize button is used to provide a localized title and / or description of the report for each locale you have defined.
Within the Translate Messages and Prompts administrative utility, it is possible to translate all the report titles and descriptions on a single screen. After entering the utility, choose the target language and then Select Metadata Category of REPORT. You will see a screen similar to the one below:
On a single screen, you can localize both the Report Title and the Report Description.