Here is a sentence from my polity book,
The Parliament is too unwieldy a body to deliberate effectively the issues that come up before it.
In this sentence 'unwieldy' is an adjective and it should be used after indefinite article.
We know that adjective is used after determiner (here 'a').
Like, an old man, a black cow, a poor boy so on...
So, why in the above sentence 'unwieldy' was used before determiner (the article 'a')?
The Parliament is [too unwieldy a body to deliberate effectively the issues that come up before it].
The degree adverb "too" is the key factor here. Adjective phrases introduced by a degree modifier like "too" can occur as pre-head modifier before the indefinite article "a", as your example demonstrates.
Without "too" the sentence would be ungrammatical.
The infinitival clause is an 'indirect complement' in that although it is a complement in the bracketed noun phrase (with "body" as head), it is licensed by the "too" that modifies "unwieldy".
