Absolutely not and this is the biggest misconception that people have with Agile. It is true that Agile promotes conversations and collaboration over documentation but documentation and, more specifically, traceability is key. The difference here is that the documentation is done using a completely different approach to the traditional cycle of requirements capture, high level design, low level design and user documentation.
One of the key principles in Agile is using user stories which are direct pointers to a conversation.
So when you hear people say "no documentation" it is an interpretation of a different process. With an Agile approach you don't spend a lot of time writing design documentation and getting sign off from the business. Your requirements are all defined as acceptance criteria (AC) in user stories agreed at the time with the product owner.
A key principle here therefore is to make sure that user stories up to date with any decisions made and there is an audit trail to those decisions and decision makers. It is a challenge to try and track down a change or what a feature should be doing if the Acceptance Criteria is not kept up-to-date.
This is another area where ServiceNow excels. Use the system that you are developing to track the user stories being implemented.
To release features you still need user guides and manuals and any configuration that needs to be recorded centrally. So as a definition of done for a delivered feature it should always include a guide or manual. Herein lies a challenge in keeping those guides up to date.
The approach we have taken is to create the user guides as the testing is being done. Automation is key here, if the testing is automated then generating automated user guides is a logical step forward so that the user guide is automatically fully in line with the currently released version. This is one of the first features that we developed because we saw the link between Agile development and the need for constantly updated user guides, this is something very few people do successfully.