When allocating a pool, I got a good error display:

However, this display doesn't show me the reason why the allocation failed - this is buried in the server response. Here's a screenshot of the information from Batch Explorer:

Ideally, this additional information would be visible in the error bar shown above.
There's a disclosure triangle at the right of the error bar that currently doesn't show any additional information; perhaps the additional reason information could be shown when the bar is expanded.
When allocating a pool, I got a good error display:
However, this display doesn't show me the reason why the allocation failed - this is buried in the server response. Here's a screenshot of the information from Batch Explorer:
Ideally, this additional information would be visible in the error bar shown above.
There's a disclosure triangle at the right of the error bar that currently doesn't show any additional information; perhaps the additional reason information could be shown when the bar is expanded.