Amount of text that can be entered

How much text can be entered into Events Administration —>Description Fields (both of them)

I get maybe 7 words, is this correct?

Also, how do i change the text when the cursor hovers over the event?

Thanks

It is limited only by DB structure
Default length of text field is limited to 255 chars
You can change text filed in database from VarChar to Text - it will change limit to 65kb.