These English sound transcriptions are a pet peeve of mine - they are simply uninformative, considering how varied English accents are. IPA is at least more or less objective.
I say more or less because the IPA transcription can be more or less rigorous (and when it comes to vowels IPA inevitably falls short).
Depending on how accurate you want to be, you might want to change the coronals to dentals (apart from [s]). As for the vowels, even though perfect accuracy can't be achieved with IPA, and even though the "exact" vowels of Sindarin are debatable to begin with, I'd suggest going with [i], [y], [u], [ɛ], [ɔ], and [a]. The final one I label as [a], but it is probably more of an [ä] in practice; the low vowel of any phonetic system that only contains one low vowel is usually just written as [a] for convenience...
- Adanel [ˈa.d̪a.n̪ɛl̪]
- Aeglos [ˈaɛ.gl̪ɔs]
- Agarwaen [a.ˈgar.waɛn̪]
- Amon Uilos [ˈa.mɔn̪. ˈui.l̪ɔs]
- Angalad [ˈaŋ.ga.l̪ad̪]
- Angrist [ˈaŋ.grist̪]
- Annúminas [an̪.ˈn̪uː.mi.n̪as]
(I omitted the arches above diphthongs because Elfdict doesn't seem to handle them well; admittedly it doesn't handle the dental diacritic well either.)
Of course, if you want to be even more accurate, you ought to consider allophonic details such as rounding before round vowels, palatalisation before [i]... But that's just the phonetician in me speaking :D
