So, if it matches an effect AND an item, it passes the string to the Wiki and leaves it to its whim which one you get.
the effect search doesn't override your ability to item-search
So your assumption is, if you don't specify a type, you want an item. Unless it matches an effect. In that case, you want an effect. Unless it matches both an item and an effect, in which case, you get whatever the Wiki gives you, which is an item.
So, if I have this right, here are the options, as you see them.
lookup item NAME
lookup effect NAME
lookup familiar NAME
If any of the above uniquely match something of their type, we take the full name of the object and pass it to the Wiki - including applying Wiki page name rules - and disambiguation rules, if that name also matches another category.
If they do NOT uniquely match within that category, it does ... what? (I would say that the user friendly reaction would be to list the ambiguous matches and let the user try again with a less-ambiguous search string.)
lookup NAME
This looks up in ALL the tables. If there is only a single match, it behaves as if that type had been specified.
If there are multiple matches - either in a single table, or across multiple - it punts to the Wiki, and you get whatever the Wiki thinks you want. Which, as in the case of "13", may or may not be what you want. Heck, maybe you really DO want random Wiki pages. In which case, why should we look in any of the tables? Why not just pass the string through and let the Wiki resolve it?
What IS your intended usage of the "no type specified" lookup?