Wrong tag names in JSF pages does not display warnings or errors on Eclipse editor

I'm working in a project migration to provide JSF 2.0 features. In this case, I'm using Eclipse Ingido as IDE and the JBoss Tools plugin. The project uses the JBoss Seam 2.3.0.Final with RichFaces 4.2.2.Final and will be deployed in the JBoss AS 7.1.1.Final.

When I try to migrate JSF pages written using JSF 1.2 and RichFaces 3.3.3.Final to the newest version of these libraries, the JBoss Tools HTML Editor in Eclipse does not display any warnings or errors in the Problems tab for wrong element names or attribute names.

Below follow an example JSF page:

<ui:define name="body">
<div class="actionButtons">
<h:botton></h:botton>
<s:button nothing="nothing" view="/GrupoEdit.xhtml" id="create"
propagation="none" value="Criar grupo">
<f:param name="grupoId" />
</s:button>
</div>
...
</ui:define>

In example, the tag <h:botton> does not exists in taglibs nor the attribute nothing in the <s:button> tag.

It is already expected that the component of the plugin does not validate this situation?