安裝時出現下面錯誤訊息：
Cannot complete the install because one or more required items could not be found.
Software currently installed: Amazon SimpleDB Management 1.0.0.v201110211341 (com.amazonaws.eclipse.datatools.enablement.simpledb.feature.feature.group 1.0.0.v201110211341)
Missing requirement: Eclipse Data Tools Platform Amazon SimpleDB UI Plug-in 1.0.0.v201110211341 (com.amazonaws.eclipse.datatools.enablement.simpledb.ui 1.0.0.v201110211341) requires 'bundle org.eclipse.datatools.sqltools.sqlscrapbook 1.0.0' but it could not be found
Cannot satisfy dependency:
From: Amazon SimpleDB Management 1.0.0.v201110211341 (com.amazonaws.eclipse.datatools.enablement.simpledb.feature.feature.group 1.0.0.v201110211341)
To: com.amazonaws.eclipse.datatools.enablement.simpledb.ui [1.0.0.v201110211341]
錯誤訊息是說缺少了 Eclipse Data Tools Platform Amazon SimpleDB UI Plug-in，但我從Eclipse Data Tools Platform (DTP)下載最新的套件還是不足。
最後直接去下載Eclipse IDE for Java EE Developers，這個版本的eclipse內建的plug-in比較完整。
再次安裝aws toolkit就可以成功了！
參考資料：
AWS Developer Forums: Eclipse AWS Toolkit install error. ...
having hard time install AWS toolkit for java and eclipse - HPCS
