Simplenotes is simple note-taking tool, based on the idea ...

[Zoli]

Did I use the comma correctly?

Here's the text:

Simplenote is simple note-taking tool, based on the idea that notes should follow a predictable and descriptive file-naming scheme.

 

[emsr2d2]

Did I use the comma correctly?

Here's the text:

Simplenote is a simple note-taking tool, based on the idea that notes should follow a predictable and descriptive file-naming scheme.

The comma is correct but note my addition of an obligatory indefinite article above.