It would be quite beneficial to have the help icon displayed to the right of the Components selection box when creating or editing an issue. No matter how carefully you try to create and name your components so that the choices are intuitive, there will ultimately be confusion from users about what component to select. When you click on the help icon it would display a list of all the components, plus the description that was added when the component was created in the project. The additional text should minimize the chance that users create an issue with an incorrect component.

For example, when I created this issue I had to choose from the 52 possible component choices in the JIRA project. I looked for a component named 'Help', but didn't find one, so the most likely choices were 'Documentation' and 'UI/Usability'. I assumed that Documentation meant documentation on the Atlassian site and not on-line help, so I picked 'UI/Usability'. However, if I could have seen the description of each component, it would have been more clear which component to select.

The same would definitely be true for component structures created by my company. There are often a couple of choices that seem plausible for component and being able to read the description would help.