"I have a friend" who is using a tool called scrumworks to assist them in reporting for their scrum process. It's a very nice tool, and I honestly cannot say there isn't a feature I wish it had or a feature I wish that it didn't have. At the very worst, I dislike it's inability to let me my friend put in a "?" for an estimate of hours (for unknown), but I'll live with that because you CAN put it as "Impeded" and just say that you don't know how to estimate it properly.

Anyhow, the issue at hand is this: The agile manifesto states:

We are uncovering better ways of developing
software by doing it and helping others do it.
Through this work we have come to value:

Individuals and interactions over processes and tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation
Responding to change over following a plan

That is, while there is value in the items on
the right, we value the items on the left more.
http://www.agilemanifesto.org/

This brings me to "Individuals and interactions over processes and tools " and the importance of this statement. It does NOT mean that we do not use tools or processes. We hold on to the ones that allow us to favor individuals and interactions and those that impeded interactivity and individuals we try to get rid of.

So let's talk about what happens when people get a tool such as scrumworks (again, a very good tool).

First, developers may not understand scrum, so now instead of learning scrum they're learning the tool and how to 'update their widgets and doo-dads' instead of figuring out what's important about scrum and why it works.They may result to using the integrated help or reading manuals instead of working with their team on the scrum framework.

Second, The tool is all or nothing in most cases. You can't modify X feature in the tool to suppory your way of doing things. Granted, Ken Schwaber would probably say "if you're modifying scrum then you're trying to hide something ugly", however I'm going to guess that 99% of organizations using agile modify it in some way... I sure haven't been in one that didn't.

thirdly, and most importantly in my opinion: Instead of having to stand up in the daily scrum and say what's impeding you, you can stick it into the tool and no longer are required to muster the courage to point it out to everyone (thusly circumventing the personal interactions and the empowerment that scrums give the team!)