In the Clone Wars episode 'Darkness on Umbara', Anakin Skywalker is told by Pong Krell that Palpatine has summoned him to Coruscant. Krell further states that the Jedi Council thought it was important enough to agree with Palpatine, which they never do. At first, I thought it was a ruse by Krell to get Anakin off Umbara, so he could mistreat/kill members of the 501st Legion, but Wookiepedia the Star Wars Wiki says that Palpatine actually did summon Anakin then. So my question is: Why was Anakin summoned to Coruscant, and was this mentioned in another episode, directly or indirectly?
Starwars.com has this synopsis
When Anakin is forced to temporarily turn over command of his clone troopers to a new commander, the Jedi Pong Krell, tensions begin to run high as the clones are assigned with a very deadly mission to take the capital of Umbara.
IMDB has this synopsis
During an assault on the shadowy world of Umbara, General Skywalker is called back to Coruscant. He has to relinquish command of the 501st legion to legendary Jedi Master Krell, who turns out to have a low opinion of Clones.
Both indicate that this is something Anakin has to do. If it were a ruse, I would expect it to be a plot point (i.e. When Anakin is tricked into relinquishing command...)