Is there any performance monitoring tool to check content db size ?

Hello,

I have following scenario :

Check volume and size of content uploaded onto the SharePoint content DB including some form of resource details like content types,docs.

Questions :

Can anyone please let me know how can we set alert when SharePoint content DB get increased ? Is there any Free Performance Tool is available which can complete the task in the above scenario ?

Please kindly suggest me.

Thanks and Regards,

Dipti