I generally would consider testing:

1. for access to resources.
2. to obtain information regarding observed challenges, and the appropriate strategies to navigate them.

As scores tend to be more stable beginning around age 8 or 9, I would wait until then, if testing for nonspecific reasons. In the interim, polarbear's advice is excellent.

In the absence of an immediate need to address one or both of those situations, we have not had our children tested, for the moment.

...pronounced like the long vowel and first letter of the alphabet...