Originating as a guitar lick written by Honeyman-Scott, the song's lyrics were explained by Hynde to be about the cockiness that one needs to effectively perform.

[3] "Brass in Pocket" originated as a guitar line that Pretenders guitarist James Honeyman-Scott played for Chrissie Hynde.

[4] Hynde got the idea for the song's title when, during an after-show dinner, she overheard someone enquiring if anyone had "Picked up dry cleaning?

"[4] The lyrics detail the female singer about to have her first sexual encounter with a particular person, with her expressing confidence that the experience will be successful.

[7][8] According to Rolling Stone magazine critic Ken Tucker, the song uses "an iron fist as a metaphor for [Hynde's] sexual clout".

[9] The Rolling Stone Album Guide critic J. D. Considine describes the song as "sassy" and credits the band for "putting bounce in each step" of it.

[10] Author Simon Reynolds similarly describes Hynde's vocals as "pure sass" and "feline narcissism", noting that she "linger[s] languorously" over the phrase "I'm special".

[8] According to AllMusic critic Steve Huey, the backbeat "meshes very nicely with Hynde's unshakable confidence, and the song never gets aggressive enough to break its charming spell or make her self-assurance seem implausibly idealized.

"[7] Huey also points out a harmonic shift in the music for the portion of the song where the singer lists the various attractive qualities she will use to make the encounter a success.

[7] Ultimate Classic Rock critic Bryan Wawzenek rated it one of drummer Martin Chambers' top 10 Pretenders songs, praising the relaxed groove and saying, "The beat is weighty but soft, and it allows plenty of room for Chrissie Hynde to side-step her way through the single.

[12] Cash Box said the song shows why Hynde was "quickly emerging as one of the bright new singer/stylists of 1980", highlighting "her sly, sexy warbling and tremendous control".