We often see resumes that are completely covered in text, where each job description is a paragraph long, and the applicant has listed every. single. thing. he did at each job. Resumes like this make our heads spin; there’s no way you can expect a hiring manager to read all that text. In fact, recruiters may just glance at the companies and job titles you’ve listed without even looking at the detailed description, especially when the resume is too wordy.
If you want to give your resume the best shot at actually getting read, you need to keep it clean and concise. Recruiters are like script readers -- they're more receptive when there's more white space. And if you're worried that you can't cover all your responsibilities without resorting to writing a paragraph, remember that you only need to include your most important and relevant skills and experience. A few short bullet points will do the trick.