Siri can't text someone even though it can call them, email them, and show me their contact information I ask Siri to "Send a text message to John Smith". I get a response, "You have two contacts named John Smith, and neither has a phone number or email address". However, if I bring up John Smith's contact information in Contacts, I see only a single card and that card has his emails and phone number. 

If I ask Siri "Show me John Smith's contact information", I see John Smith's contact information. If I ask Siri "Where is John Smith?" Siri will show me where John Smith is in the Find my Friends App. If I ask Siri "Email John Smith", Siri replies "Which email address for John Smith" and shows me all of his email addresses. If I say "Call John Smith", Siri calls John Smith.

And, if I bring up the contact, and press the little speech bubble, I can text John Smith that way. And, I can also ask Siri to display John Smith's contact information and send him text that way too.

The issue only seems to be with text messages. John Smith also has an iPhone and uses iMessage.

Any idea how I can get Siri to find John Smith's email address or phone number when I text him? I have no problems with email or phoning John Smith through Siri -- just texting through Siri.
Okay. I fixed the problem — at least so far.
Deleting the entry did nothing. I recreated the entry, it initially worked, and then failed five minutes later with the same problem.
On my iPhone, entries are &quot;unified&quot;. For example, my wife has an entry for someone, and I have an entry for someone, it shows up on my iPhone as a single entry. On my iPad, these show up as multiple entries. If Facebook creates an entry, a third one shows up.
I want to my iPad, and there were three entries for this name — two had email and phone numbers and one did not.
Deleting that mysterious third entry worked for about two minutes, but it reappeared a minute later, and I had the same issue again. I ended up editing that third entry and added a phone number and email addresses. That allowed me to text John Smith through Siri. It so far has held for two days. I can once again text John Smith through Siri. However, other people who have Facebook profiles and are in my phone book aren't an issue. It was just this one.

Addendum
The problem was tracked down to Facebook being allowed to munge my address book. This user didn't have phone or email information in Facebook, so Siri must have seen the Facebook info, and tried to use that. On my iPhone, the contact entries are unified, so I see both what Facebook puts in and my entry.
Turning off Settings-&gt;Facebook-&gt;Contacts solved the issue.
There maybe similar issues with other contact applications like Twitter and Outlook which might cause Siri not to see the information you have for a contact. Turning off these app's ability to update your contacts may solve the issue.