1PasswordAgent.app wants to use your confidential information stored in "1Passwd Master Password" in your keychain

The issue is related to the "Never prompt for master password" option in 1Password's preferences (on the Security pane). In some cases OS X does not remember your choice if you select "Always Allow".

We are investigating a fix for the issue if it is something we can resolve on our end (rather than a problem in OS X itself), but the reality is that we don't recommend using the "Never prompt for master password" option for security reasons. The option is already removed from the version of 1Password available on the Mac App Store, and it's unlikely to return in future versions of 1Password.

To achieve similar functionality, we suggest disabling 1Password's auto-lock settings. That way 1Password will stay unlocked all day long. You will only need to type your master password after a fresh login to your OS X account. This obviously has the added benefit of not recording your extremely important master password in the [insecure by default] OS X keychain.

If you use a laptop, enabling only the "Lock when sleeping" option means that 1Password will stay unlocked until you close the lid on your MacBook. A convenient way to stay secure on the go!