I don't think the x-refs are needed.
"stimulus" is sense 2.

@@ -16 +15,0 @@
-<xref type="see" seq="1594190">刺激・しげき・1</xref>
@@ -20,2 +18,0 @@
-<gloss>stimulation</gloss>
-<gloss>stimulus</gloss>
@@ -25 +21,0 @@
-<xref type="see" seq="1594190">刺激・しげき・2</xref>
@@ -26,0 +23,2 @@
+<gloss>stimulus</gloss>
+<gloss>spur</gloss>

GG5: a stimulant; an excitant; a stimulative; an irritant.
中辞典: a stimulant; an irritant; an excitant

Given the overall set of glosses, I think the "(drug)" qualifier is not needed or appropriate. I have no problem with including "irritant". It's fine in the context.

@@ -17 +17,3 @@
-<gloss>stimulant (drug)</gloss>
+<gloss>stimulant</gloss>
+<gloss>excitant</gloss>
+<gloss>irritant</gloss>

刺激剤	13305	50.2%
刺激薬	13120	49.5%
刺戟剤	100	0.4%
刺戟薬	0	0.0%

https://ejje.weblio.jp/content/刺激剤
日本語WordNet(英和)での「刺激剤」の英訳
刺激剤
incentive, motivator, inducement
積極的な動機づけの効果をもたらすもの
(a positive motivational influence)


EDR日英対訳辞書での「刺激剤」の英訳
刺激剤
読み方 シゲキザイ
encouragement

Fixed kanji.

Added the xref in place of trying to clarify somehow.  there are lots of "stimulant" entries that have similar (and robust) n-gram counts. This one is notable in that the dictionary specifically uses it in a non-chemical context ("failure is a good motivator"). daijs: その失敗がよい―になった」.  It's also notable for *not* being listed as a "stimulant" term on wikipedia's chemical stimulants page as a synonym.

Weblio has a large collection of good glosses from other sources if you'd like to choose some...
https://ejje.weblio.jp/content/刺激剤

I am extremely suspicious of glossing this entry as "irritant" (even though you'll find this on weblio, and on other "stimulant" entries).  If it's in the context of "non-刺激剤" or "low-刺激剤", then perhaps low-irritant or non-irritant/anti-irritant makes sense.  But I don't think it would be used as "irritant" in a non-negated context...

Look at this terrible gloss/translation, for example:
呼吸刺激剤
respiratory irritant《医》〔睡眠時無呼吸症候群などの治療に用いられる〕
The example sentence says 呼吸刺激剤 would be used to *treat* sleep apnea.  It's a respiratory stimulant, not an irritant....
https://eow.alc.co.jp/search?q=刺激剤

@@ -5 +5 @@
-<keb>刺戟剤</keb>
+<keb>刺激剤</keb>
@@ -8 +8,2 @@
-<keb>刺激剤</keb>
+<keb>刺戟剤</keb>
+<ke_inf>&sK;</ke_inf>
@@ -15 +16,9 @@
-<gloss>stimulant</gloss>
+<xref type="see" seq="1594190">刺激・しげき・1</xref>
+<gloss>stimulant (drug)</gloss>
+<gloss>stimulation</gloss>
+<gloss>stimulus</gloss>
+</sense>
+<sense>
+<pos>&n;</pos>
+<xref type="see" seq="1594190">刺激・しげき・2</xref>
+<gloss>motivator</gloss>