Few studies have investigated the composition of male couples’ sexual agreements and whether their agreement composition differs by dyad HIV serostatus. To help assess the utility that agreements could have for sexual health and prevention, the present study analyzed dyadic paradata collected from an acceptability project of an eHealth HIV prevention toolkit intervention with 42 male couples in Lima, Peru (16 serodiscordant, 12 seroconcordant positive, 14 seroconcordant negative). Couples used the toolkit as designed, which included an agreement builder activity to encourage formation of a tailored agreement by selecting items from five categories (wellness, sex with partner, sex with others, social etiquette, substance use). The number of items couples included in their agreement varied (range: 7–59), and did not differ by dyad serostatus. For agreement composition, couples included the highest number of items about wellness, followed by sexual behaviors with the partner, and social etiquette. Between one- and two-thirds of couples included regular HIV/STI testing. However, far fewer specified guidelines about condom use and no couples included biomedical HIV prevention strategies. Findings suggest additional intervention mechanism(s) (e.g., prompts, algorithms) may be needed to encourage couples to include HIV/STI prevention strategies in their agreements while also balancing their sexual health preferences.