Under the latest release, 0.26, when I manually set the state of a device under the developer tools it appears to drop all attributes. I haven’t been able to manually add the Attributes back. My feeling is its might be a bug from the new Dev Tools updates.
The only reason I do this is for Locative and Device tracking. On restart it shows the devices as Away (not_home), so I manually set them to Home.
Edit: It seems that after a state change it restores the Attribute data and all automation works fine.