The description must reflect the actual engagement being presented. It should not invent a position assembled from competing proposals.
Evaluate each offer on its own facts
Identify which responsibilities belong to which employer. A role that qualifies on its real duties is different from a description created merely to resemble a listed profession.
The decisive inquiry is whether a Canadian or Mexican citizen has a genuine, temporary professional engagement that matches a USMCA-listed occupation and its exact qualification rule. Obtain a transcript or institutional letter stating whether the credential was formally conferred, the award date and the field of study, then compare those facts with the precise qualification rule for the proposed profession. The parties should make their offer, work order, reporting structure, location, and requested period agree before choosing either a Canadian applicant’s port-of-entry presentation or an employer-filed Form I-129 route. The proposed duties must still involve qualifying professional activity; neither the certificate nor the employer’s willingness to call the applicant a chemist settles the entire case. Where biology is clearly the core and the adjacent work supports it, the match is easier to present; where biology is a minority function inside a primarily different discipline, the position may not fit the category however strong the applicant's background.