Most cover letters are noise — templated, generic, and written to check a box rather than communicate anything real. But the ones that are actually written well reveal things about a candidate that no resume can: how they think, how they communicate, and how seriously they're taking this specific opportunity.
Here's how to read them in a way that extracts real signal.
The First Paragraph Test
Read the opening paragraph and ask one question: is this specific to your company and role, or could it have been sent anywhere? A cover letter that opens with a specific observation about your company, a concrete reason why this role appeals to them, or a direct connection between their experience and your stated needs signals a candidate who does their homework and communicates with purpose.
A letter that opens with "I am excited to apply for the role of X at your company" followed by a summary of their resume tells you the candidate either didn't put in the effort or doesn't know how to communicate beyond a template. That itself is information.
What Strong Cover Letters Actually Do
The best cover letters don't summarize the resume — they add to it. They explain things the resume can't: why a career change makes sense, what drew them to this specific company, what problem they're most excited to work on, or why a gap in their history exists. If a cover letter is just a prose version of the resume bullet points, it's contributing nothing.
Look for candidates who use the cover letter to address something that might otherwise raise questions. A candidate who proactively explains a career pivot, a gap, or an unconventional background in a clear and confident way is showing self-awareness and communication skill simultaneously.
The Specificity Signal
The most reliable signal in any cover letter is specificity. Vague enthusiasm is easy to produce and means nothing. Specific knowledge — about your company's product, your industry's current challenges, or a recent development relevant to the role — requires actual effort and signals genuine interest.
A candidate who references something specific about your product, mentions a recent company announcement, or connects their experience to a concrete challenge your industry faces is telling you they approached this application like a professional, not a numbers game.
When to Ignore the Cover Letter
Some strong candidates are poor cover letter writers. Technical roles especially attract candidates who are excellent practitioners and weak self-marketers. Don't eliminate a technically strong candidate solely because their cover letter is flat. Use the resume as the primary filter and the cover letter as supplementary signal — a positive if strong, neutral if weak, negative only if actively concerning.
The Red Flag Version
A cover letter that contains factual errors about your company, refers to you by a competitor's name, or describes enthusiasm for a role that doesn't match what you posted is worth noting. These errors reveal either carelessness or a spray-and-pray application approach — neither of which is a great start.
Use RecruiterSignal to analyze candidates holistically and surface the signals that actually predict performance for your specific role.