al-Tayyib (the Good) is one of the names of Allaah, may He be exalted
Question

Is al-Tayyib (the Good) one of the names of Allaah, or is it a description? What is the guideline for distinguishing names from descriptions or attributes?.
Praise be to Allah.Firstly: 
Is at-Tayyib (the Good) one of the sublime names of Allah?
The scholars differed as to whether at-Tayyib is to be regarded as one of the names of Allah, may He be exalted. The majority are of the view that it is not one of the divine names, because there is no evidence to suggest that at-Tayyib may be regarded as one of the sublime names of Allah. 
Secondly: 
The difference between names and attributes: 
In Fataawa al-Lajnah al-Daa’imah (3/16) there is a question about the difference between names and attributes. The answer was: 
The names of Allaah are all those that refer to the Divine Essence with attributes of perfection that exist in Him such as al-Qaadir (the All-powerful), al-‘Aleem (the All-knowing), al-Hakeem (the Wise), al-Samee’ (the All-hearing), and al-Baseer (the All-seeing). These names refer to Allaah, and to what exists in Him of knowledge, wisdom, hearing and seeing. As for the attributes, these are attributes of perfection that exist in His essence such as knowledge, wisdom, hearing and sight. The name points to two things and the attribute points to one thing. It may be said that the name includes the attribute and the attribute implies the name. End quote. 
See also question no. 22642. 
Shaykh ‘Alawi ibn ‘Abd al-Qaadir al-Saqqaaf said: In order to know what distinguishes the name from the attribute, and the attribute from the name: 
1 – With regard to names, attributes may be derived from them, but with regard to attributes, names cannot be derived from them. From the names of Allaah al-Raheem (the Most Merciful), al-Qaadir (the All-powerful) and al-‘Azeem (the Almighty) are derived the attributes of rahmah (mercy), qudrah (power) and ‘azamah (might), but from the attributes of will, coming and plotting we cannot derive names such as “Willer”, “Comer” or “Plotter”. 
His names are descriptive, as Ibn al-Qayyim said in al-Nooniyyah. 
2 – The names cannot be derived from the actions of Allaah. The fact that He loves and hates and gets angry does not mean that we can derive names such as “Lover” “Hater” or “Angry”. As for His attributes, they may be derived from His actions. So it is proven that He has the attributes of love, hate and anger etc., hence it is said that the category of attributes is broader than the category of names.  
Madaarij al-Saalikeen (3/415) 
Thirdly:  
The names and attributes of Allaah may both be used when seeking refuge and swearing oaths, but a distinction is made when it comes to describing people as slaves of Allaah and supplication. We may describe people as His slaves by using His names, so we say ‘Abd al-Kareem (slave of the Most Generous), ‘Abd al-Rahmaan (slave of the Most Gracious) and ‘Abd al-‘Azeez (slave of the Almighty), but we do not describe people as His slaves by using His attributes, so we do not say ‘abd al-karam (slave of generosity) or ‘abd al-rahmah (slave of mercy) or ‘abd al-‘izzah (slave of might). Similarly, Allaah is called upon by His names, so we say Ya Raheem, arhamna (O Most Merciful, have mercy on us) or Ya Kareem, akrimna (O Most Generous, honour us) and Ya Lateef, altif bina (O Most Kind, be kind to us), but we do not call upon His attributes and say, O mercy of Allaah, have mercy on us, or O generosity of Allaah, or O kindness of Allaah. That is because the attributes are not the same as the One described. Mercy is not Allaah, rather it is an attribute of Allaah; the same applies to might etc. These are attributes of Allaah but they are not Allaah, and it is not permissible to describe anyone as a slave of anything but Allaah, or to call upon anything but Allaah, because Allaah says (interpretation of the meaning): 
“they (believers) worship Me and do not associate anything (in worship) with Me” [al-Noor 24:55] 
“Invoke Me [i.e. believe in My Oneness (Islamic Monotheism) and ask Me for anything] I will respond to your (invocation)” [Ghaafir 40:60]
End quote from Sifaat Allaah ‘azza wa jall al-Waaridah fi’l-Kitaab wa’l-Sunnah, p. 17 
As for the difference between discussing the names and attributes of Allaah and what comes under the category of talking about Him, there are two points: 
1 – The divine names and attributes are tawqeefi i.e., limited strictly to that which is mentioned in the Qur’aan and saheeh Sunnah. So it is not permissible to ascribe to Allaah anything except that which He has ascribed to Himself or His Messenger (peace and blessings of Allaah be upon him) has ascribed to Him. But when speaking of Him, it is permissible to speak of Allaah in ways that are not narrated in the Qur’aan or Sunnah if the meanings are sound, such as saying He is eternally good and very generous.  
2 – His names are beautiful and His attributes are sublime, as He says (interpretation of the meaning): 
“And (all) the Most Beautiful Names belong to Allaah, so call on Him by them, and leave the company of those who belie or deny (or utter impious speech against) His Names. They will be requited for what they used to do” [al-A’raaf 7:180] 
“For those who believe not in the Hereafter is an evil description, and for Allaah is the highest description. And He is the All‑Mighty, the All‑Wise” [al-Nahl 16:60]
al-Shawkaani said in Fath al-Qadeer (4/314): al-Khaleel said: “The highest description” means: His is the highest (or most sublime) description in the heavens and on earth. End quote. 
As for speaking about Allaah, it is permissible to speak of Allah in ways that imply no imperfection, even if it is does not imply the highest perfection, such as saying that Allaah exists from eternity, or saying that He exists, or referring to Allaah as a “thing” or “something” and so on. Allaah says (interpretation of the meaning): “Say (O Muhammad صلى الله عليه وسلم): What thing is the most great in witness? Say: Allaah (the Most Great!) is Witness between me and you” [al-An’aam 6:19]. 
Ibn al-Qayyim (may Allaah have mercy on him) said: You should note some things here: 
(i)That which is included under the heading of speaking about Him (may He be exalted) is broader in scope than that which comes under the heading of His names and attributes, such as referring to Him as a ‘thing” or “something”, or saying that He exists and is self-sufficient, because this is talking about Allaah and that does not come under the heading of His beautiful names or sublime attributes.
(ii)If a word may imply perfection or imperfection, depending on the context, then it is not one of His names, rather may be used to describe Him when it implies perfection, such as willing, doing and making. These words are not included in His names, hence the one who calls Allaah al-Saani’ (the maker) is mistaken. Rather He is the One Who does what He wills, for will, doing and making are words that may imply perfection or imperfection. Therefore Allaah attributed to Himself that which implies the greatest perfection in action and the greatest perfection when speaking of Him.
(iii)Talking about His actions does not mean that we can derive names from these actions, as some later scholars mistakenly did and included among His names al-Mudill (the Misguider), al-Faatin (the Tempter) and al-Maakir (the Plotter) – exalted be He above what they say. These names cannot be given to Allaah, may He be glorified, because Allaah did not ascribe these names to Himself, rather He only mentioned these things as specific actions in specific circumstances, therefore He should not be named on the basis of these actions. …
(vii) The names and attributes that may be given to Him are tawqeefi, i.e., limited to those that are found in the Qur’aan and saheeh Sunnah, but when it comes to speaking about Him, the terms used do not have to be tawqeefi, such as saying that He exists from eternity, or referring to Him as a “thing” or “something”, or saying that He exists and is self-sufficient.  
These are the decisive guidelines on the issue of whether the names of Allaah are tawqeefi or is it permissible to call Him by names that are not narrated in Qur’aan and Sunnah? 
(viii) With regard to the names of Allaah, such as al-Samee’ (the All-hearing), al-Baseer (the All-seeing) and al-Qadeer (the All-powerful), it is permissible to derive from them nouns which may be attributed to Him, such as hearing, seeing and power, and it may be said that He did those actions, such as saying “Allaah has indeed heard” [al-Mujaadilah 58:1] and “So We did measure; and We are the Best to measure (the things)” [al-Mursalaat 77:23].  This applies if the verb is transitive. If it is intransitive, such as al-Hayy (the Ever-Living), then it this case we do not use the verb when speaking of Him, rather we use the verbal noun, but not the verb. "(Badaa’i’ al-Fawaa’id  1/170). 
And Allaah knows best.