Update from 31 January 2024

I believe this is still an issue, I just want to add here a link to our current Jira Cloud docs: Edit or delete a custom field
 

Jira allows you to define a description of a custom field. If the field configuration descriptions are left empty, then the original description text will appear when you create or edit an issue and as help text in the Issue Navigator. You can define different descriptions in each field configuration to override the description you added.

For example, if a custom field "My Field" is defined with a description of "This is my field" and no field configuration changes are made, then the displayed text will be "This is my field" as expected. If field configurations are used and a description "This is my excellent field" is set for the custom field in the field description, then the displayed text will be "This is my excellent field".

Original description:

The way custom field description hierarchy is handled within JIRA seems to be counter-intuitive to some of our customers.
Examples below:

• https://answers.atlassian.com/questions/62727/jira-v5-strange-custom-field-behavior
• https://answers.atlassian.com/questions/47433/how-to-update-custom-field-description
• https://answers.atlassian.com/questions/61711/custom-field-description-not-displayed
• https://answers.atlassian.com/questions/13046/custom-field-descriptions-not-displaying-correctly

Perhaps we can find a way to clarify the hierarchy with the field configuration to customers that are editing on creating a description to a custom field.

Our documentation states:

Changing the description of a custom field

Not changing the description in a field configuration means that any changes you make to a custom field's description are not seen.

JIRA allows you to define a description of a custom field, and if the field configuration descriptions are left empty then the original description text will appear when you create or edit an issue, and as help text in the Issue Navigator. However you can also define different description texts in each field configuration and this will override the original field description text.

For example if a custom field "My Field" is defined with a description of "This is my field" and no field configuration changes are made, then the displayed text will be "This is my field" as expected. If field configurations are used and a description "This is my excellent field" is set for the custom field in the field description, then the displayed text will be "This is my excellent field".