Cv Cover Letter

Cover letter, from evidence

A cover letter is a volatile document: a mediocre one is ignored, but a wrong one disqualifies before anything true about the applicant is read. The upside is bounded and the downside is not, so this skill biases toward fewer sourced claims over more impressive ones, and toward a shorter letter over a padded one.

Its purpose is to reduce the cost of producing a true letter, not to produce a persuasive one. cv-evidence-base makes a weak CV less weak; this makes an expensive document cheap without letting it drift from the facts.

What the evidence actually supports

This skill's rules come from measured outcomes, not from career-advice convention. The full synthesis with citations is in references/evidence.md. The four that change behaviour:

• Composition beat tailoring. Detail, clarity and structure predicted more interviews (β = 0.20, p = .016) and a shorter search; tailoring predicted nothing (p = .34). Wingate, Robie, Powell & Bourdage (2025), Int. J. Selection and Assessment.
• Mirroring the posting has stopped signalling. After an AI writing tool launched on a large labour platform, the correlation between a letter's textual alignment and callbacks fell 51%, and employers moved to prior work history. Cui, Dias & Ye (2025). Replicated independently on different data by Galdin & Silbert (2025).
• A signal only carries information if it is costly to fake. Spence (1973). An adjective is free; a checkable fact is not. That is the whole basis of the rules below.
• Editing the draft correlated with success. So the output is a draft with the judgment calls left open, never a finished letter.

Do not cite recruiter surveys — the circulating figures range from 83% to 26% on the same question and every one is published by a company selling cover-letter tools.

Step 1 — Is this worth writing?

Read the posting for stated hard requirements: a language, a licence, a work permit, a named years-of-management threshold, an on-site requirement. Check each against what the applicant has given you.

If a stated requirement clearly fails, say so before writing anything. An hour spent on an application that screens out on a language requirement is the burden this skill exists to remove. Say which requirement, say it is the user's call, and write the letter if they still want it.

Do not treat a preference as a requirement — "German a plus, not required" is not a barrier.

Step 2 — Take the posting apart

Work from what the posting requires, separated from what it advertises. Most of a job advert is marketing; the requirements are usually a short list inside it.

Look for a section describing what success looks like in the role, or the first ninety days. Where it exists it is the most useful part of the advert: the employer stating their own criteria, so nothing has to be inferred about what they want.

Never assert a problem the employer has not stated. Diagnosing a business to someone who works there, from a guess, is the failure that cannot be recovered. If the posting says cloud spend is outpacing revenue, that is theirs and quotable. If it does not, you do not know. A question is safe where a diagnosis is not: "I would want to understand how you currently handle X" claims nothing.

Step 3 — Every claim is STATED or DERIVED

Derived claims are not forbidden. They are surfaced. Put them in the claims table marked derived so the applicant confirms them. Two baseline runs of this task both produced "sixteen years" from a date range and stated it as fact — never said by the person whose letter it is.

A year-count derived from a CV is not merely unverified. It is biased downward. A CV truncates early history by design — roles beyond roughly fifteen years are routinely dropped or compressed — so the earliest date on the page is a presentation choice, not a career start. Measured on a real pair: the CV's earliest year was 2000; the evidence base held 1997–2010 and named 1995. Arithmetic on that CV understates its owner by five years, silently, and reads as confident.

So the rule is not only "confirm it". It is: the CV cannot answer how long someone has worked. Ask, or take it from the evidence base, or leave it out. Dated facts already show span without anyone having to total them.

Anything that is neither stated nor derivable does not go in the letter. Not softened, not hedged — out.

Step 4 — Choose two or three claims, then stop

Impact comes from selection, not invention. The evidence base holds twenty true things; the posting decides which two or three to spend.

There is no word count. The 250–400 word rule prescribed by most cover-letter tools has no empirical support — nor do one-inch margins, 10.5–12pt type, or avoiding the first person. The letter ends when the sourced claims end. A letter carrying three claims in three paragraphs is finished; adding a fourth paragraph to reach a length adds words that signal nothing.

Lead with the strongest sourced claim, not with the fact of applying. The reader already knows which role this is — it is in the subject line, and "I am writing to apply for" spends the most expensive sentence in the letter on nothing. Wingate et al. found detail predicted outcomes; a statement of applying carries none. Open on the checkable fact that best answers what the posting asks for.

This is the one place where impact and evidence pull the same way. The opening does not need a manufactured hook — it needs the best true thing, first.

Prefer the claim that is checkable and specific over the one that sounds impressive. "Reduced critical findings from 180 to 12 over nine months" survives contact with an interview. "Extensive security experience" does not, and costs nothing to write, which is precisely why it carries no information.

Step 5 — Register

Invoke clear-and-human for the prose. Do not reinvent its rules here.

Two failures specific to this document, both of which reproduced across baseline runs:

The pitch register. "The discipline I'd bring", "a track record of taking ownership when it counts", "doing it in a way that earns their trust rather than just meeting a spec", "sits at the intersection of". These are unsourceable by construction — that is why they are empty, not merely why they read badly. Cut them and the letter gets shorter and stronger at once.

Conventions differ by market. A German Anschreiben is more formal and more factual than a US cover letter, and the confident-pitch register that American advice teaches can read as overclaiming elsewhere. Where the applicant's market is known, follow it; where it is not, the restrained factual version is the safer default and the one the evidence supports anyway.

Step 6 — Check coherence with the CV

Every claim in the letter must appear in the CV the applicant is sending. Two documents agreeing on specifics is expensive to fake, and it is the signal that survives now that fluent tailored prose is free.

A claim in the letter that is absent from the CV is a flag, not an error — it may mean the CV is missing something worth adding, which is cv-and-human's job. Report it; do not silently drop it or silently rewrite the CV.

Output

1. A triage line — either "no stated requirement fails" or which one does.
2. The draft. No contact-block boilerplate unless asked; the applicant has that.
3. The claims table — every claim, its source line, stated or derived, and whether the CV corroborates it. This is what makes the rules checkable rather than promised.
4. Open decisions, listed. Why this employer specifically, relocation, notice period, anything only the applicant knows. Do not guess these and do not write around them — leave them marked in the draft.
5. What was refused, and why. A requirement with no supporting evidence is named here.

What this skill does NOT do

• It does not invent a metric, a date, a duration or a scope.
• It does not diagnose the employer. No problem is attributed to them that they have not stated.
• It does not pad to a length, and it has no target length.
• It does not write "passionate about", or any claim of enthusiasm in place of evidence.
• It does not cite recruiter-survey statistics.
• It does not write or edit the CV — that is cv-and-human.
• It does not decide whether to apply. It reports a failed hard requirement; the choice is the applicant's.
• It does not promise an outcome. Nothing here predicts a callback.

Requirements

Three inputs, supplied by the user — this skill does not go looking for files:

1. The posting. A URL, a pasted advert, or a file. Any source; not only LinkedIn.
2. The CV being sent.
3. evidence-base.md from cv-evidence-base, if it exists.

Running without an evidence base is supported and produces a true letter. Every rule still applies; the CV is simply the only source. Say so when it costs something. A CV compresses early roles by design, so if the posting asks for something the CV cannot evidence and the letter comes out thin, name that — "the strongest claim available from the CV alone is X; if you have run cv-evidence-base, there may be a better one it dropped" — rather than padding to cover the gap. Do not present this as a blocker and do not refuse to write.

The CV family has no shared path convention and this skill does not invent one.

Provenance

Structure — hook types, opening don'ts, and the underqualified / overqualified / career-change scenarios — adapted from Paramchoudhary/ResumeSkills (MIT). Its "include at least one specific metric" checklist item and its 250–400 word rule are deliberately not carried over: the first is an instruction to produce a number without a source, and the second has no empirical basis.