Agara is a corruption of the Sanskrit word agrahara. However, according to Sthalapurana (corpus of texts on the origins and traditions of particular Tamil Saiva shrines), a king named Vishnusarma who once visited the place was bitten by a cobra and got rid of his poison by prayers to Ramaesvara and Narasimha and since then the village came to be known as agara (free from gara or poison).
Agara has four old temples dedicated to Ramesvara, Narasimha, Varadaraja and Durga, all of which are in a dilapidated condition however the Narasimha temple has been renovated. In the Narasimha temple, the sanctum sanctorum (garbagriha) and vestibule (sukhanasi) belong to the original structure are of an oval shape. The closed hall of worship (navaranga) has two entrances with porches on the west and north, and opposite to the north entrance is a cell in which the metallic image of the god is kept. Narasimha is a fine figure about four feet high with a halo seated in the posture of yoga or meditation. This image is said to represent five kinds of Narasimha, a peculiarity not found elsewhere - Yoga-Narasimha seated in yoga posture, Laksmi-Narasimha having a figure of Lakshmi sculptured in his chest, Ugra-Narasimha on account of the presence of a third eye on the forehead, Jvala-Narasimha as having flames represented near the ears and Prahlada-Narasimha on account of the presence of a figure of Prahlada at the side.
During the restoration of Narasimha temple, many inscribed stones were chiseled out and displaced and so hardly any complete epigraph could be recovered. Though one of the fragments of inscriptions can be assigned close to the tenth century CE. Another fragment records a grant made by the Hoysala king Vishnuvardhana (1108–1152 CE).
Reference: MYSORE GAZETTEER, Vol 5, pp. 632-633.