robots.txt disallow without wildcard

I have the following code in my robots.txt

to prevent bots accessing hxxp://example.com/tos (terms of service).
However this results googlebot complaining it is also blocking its access to hxxp://example.com/toscana even though there is no wildcard in disallow!
How do I tell the bot to ignore /tos only?

how about trying:

Disallow: /tos$

or

Disallow: /tos/

thanks, $ at the end was what I needed