Knowing how to write a job description sounds basic, but most small businesses get it wrong in the same predictable ways. They copy a template, cram in every duty they can think of, then wonder why the applicants are either unqualified or wildly overqualified. A good job description is not a legal document and it’s not a wishlist, it’s a decision tool. Done properly, it saves you time, reduces bad hires and makes interviews easier because everyone is working from the same definition of ‘good’.
In this article, we’re going to discuss how to:
- Define the role in business terms before you write a single requirement.
- Build a job description structure that filters in the right people and filters out noise.
- Set fair, clear expectations on pay, flexibility and progression without overselling.
Start With The Hiring Problem You’re Actually Solving
Before you draft anything, write 3 lines for yourself: what’s broken, what ‘fixed’ looks like and what happens if you don’t hire. This keeps you honest, especially when multiple stakeholders want to bolt on extra responsibilities.
Use a simple frame:
- Outcome: What must be true in 3 to 6 months for this hire to be considered a good decision?
- Work: What work produces that outcome, week to week?
- Constraints: Budget, time zones, compliance, on-site needs, peak periods.
If you can’t describe the outcome, you’re not ready to hire. You’re ready to think, or to buy time with a contractor.
How To Write a Job Description: A Practical Structure
If you want fewer irrelevant applications, your job description has to be scannable and specific. Candidates skim, they don’t study. A good structure also helps you stay consistent with fair hiring practices, which matters under UK equality law. ACAS has practical guidance on recruitment and avoiding discrimination in ads: https://www.acas.org.uk/recruitment.
1) Job Title That Matches The Market
Use the title candidates actually search for, not your internal label. ‘Marketing Ninja’ is funny until it means the right people never find the role. If the job blends areas, pick the dominant skill set in the title and reflect the blend in the summary.
Keep seniority honest. Calling something ‘Manager’ when there are no reports creates suspicion and attracts the wrong level of applicant.
2) Two-Sentence Role Summary (Outcome First)
Open with what the person will be accountable for and who they work with. Avoid a long company intro. People want to know what they’ll do, how success is judged and whether the situation is sane.
Example: ‘You’ll own our monthly management accounts and cash flow reporting so the founders can make week-to-week decisions with confidence. You’ll work closely with our bookkeeper and external accountant, and you’ll improve the quality and timeliness of financial data across the business.’
3) What You’ll Be Doing (5 to 8 Bullets)
This is the heart of the ad. Keep it tight and concrete, written in plain verbs. If you’re listing 15 duties, you don’t know what matters.
- Run X (process) on Y cadence (weekly, monthly), producing Z (output).
- Work with A (stakeholder) to improve B (metric or system).
- Handle C (situations) within D (limits and escalation route).
Be honest about the messy parts. If the data’s poor, say so. If the role includes customer complaints, say so. People who can deal with reality are often the people you want.
4) Must-Haves Versus Nice-to-Haves (Keep Must-Haves Short)
Most job ads fail here by turning preferences into demands. That narrows your funnel and can accidentally screen out strong candidates who’ve taken a different path. Put a hard cap of 5 must-haves, written as evidence, not vibes.
Must-have examples that are testable:
- ‘2+ years managing paid search budgets over £X per month’
- ‘Comfortable producing weekly reporting in Excel or Google Sheets’
- ‘Experience dealing with suppliers and negotiating basic terms’
Nice-to-have examples:
- ‘Experience in our sector’
- ‘Familiar with X tool’
Do not use ‘must be a self-starter’ as a requirement. It’s meaningless and often a sign you haven’t set up the work properly.
5) How You’ll Measure Success (3 to 5 Lines)
This section is your best filter. It also forces you to think about onboarding and what’s realistic.
- First 30 days: Learn systems, ship first output, build stakeholder map.
- First 60 to 90 days: Own the workflow end to end, remove a recurring pain point.
- Ongoing: Hit agreed cadence, quality standard and service level.
Keep it grounded. If you promise ‘double revenue’ or ‘transform operations’ you’re hiring for a fantasy, not a role.
6) Practicalities: Location, Flexibility, Pay Range And Benefits
Ambiguity here wastes everyone’s time. If the role is hybrid, say how many days on-site and where. If it’s remote, state any limits such as UK-only for payroll, or time zone overlap.
Pay transparency is increasingly expected. In the UK there’s no single universal requirement to post a range for all roles, but the direction of travel is clear and it improves the quality of matches. If you can’t publish an exact range, publish a sensible band and say what affects the final figure, for example experience level or specific responsibilities.
When describing benefits, keep it factual. ‘Great culture’ is not a benefit. A pension, 25 days holiday, private healthcare, training budget and clear working hours are benefits.
Write For The Right Candidate, Not For Everyone
There’s a temptation to make the role sound like it could suit anyone, because you want more applications. That produces the opposite outcome: the right people don’t apply because the job sounds vague, and you get a pile of random CVs.
Decide who you’re aiming at, then be explicit. Is this a role for someone stepping up, or someone who’s done it before? Do you need a generalist, or a specialist? If it’s a step-up role, say what support looks like, for example weekly 1:1s, templates, and access to experts. If it’s for an experienced hire, say what autonomy and constraints look like.
Reduce Risk With Clear Boundaries And Fair Language
A job description is part of your risk management. It sets expectations that affect performance, probation, disputes and retention. GOV.UK has plain-English guidance on employing staff and your responsibilities.
Practical guardrails to include:
- Reporting line: Who they report to and who they work with.
- Decision rights: What they can decide alone, and what needs sign-off.
- Hours: Expected working pattern, especially if you operate evenings or weekends.
- Travel: If travel is required, state frequency and typical notice.
Keep language neutral. Avoid gender-coded or age-coded phrases like ‘young and energetic’. If you require certain checks for regulated work, state that clearly and lawfully.
Common Job Description Mistakes That Waste Your Time
These are patterns you’ll see across early-stage companies and established small firms alike:
- Copying a generic template: It reads like every other ad and attracts every other applicant.
- Listing every tool under the sun: Tools change, judgement and fundamentals matter more.
- Overstating seniority: It creates mismatch, resentment and early exits.
- Hiding the hard parts: The role still includes them, you just find out later in the worst way.
- No success definition: If you can’t explain how you’ll judge performance, the candidate can’t self-select.
When you’re learning how to write a job description that works, the easiest improvement is to cut, not add. Fewer, clearer statements beat long lists every time.
A Quick Pre-Posting Checklist
Before you publish, read your job description and answer these questions:
- Could a good candidate tell what the job is in under 30 seconds?
- Do the must-haves map to the work, or to preferences?
- Is the pay and working pattern clear enough to prevent wasted interviews?
- Would you be comfortable defending the wording as fair and job-relevant?
For language and fairness, it’s worth scanning ACAS guidance again and checking your wording against it.
Conclusion
A strong job description is an operating document, it turns a fuzzy ‘we need help’ into a defined outcome and a realistic set of responsibilities. It also makes your hiring process calmer because candidates self-select more accurately. If you treat it as a filtering tool and a promise you can keep, you’ll spend less time sorting CVs and more time talking to people who fit.
Key Takeaways
- Start with the business outcome, then write responsibilities that clearly produce it.
- Keep must-haves short and testable, and separate them from nice-to-haves.
- State practicalities plainly, especially pay band, location and how success is measured.
FAQs
How long should a job description be?
Long enough to explain outcomes, responsibilities and practicalities without turning into a novel, typically 500 to 900 words. If you need more than that, you probably haven’t prioritised what matters.
Should I include a salary range in the UK?
It’s not always legally required for every role, but it usually improves applicant quality and reduces wasted time. If you can’t give an exact number, provide a realistic band and explain what drives the final offer.
What’s the difference between a job description and a person specification?
A job description explains the work and accountabilities, while a person specification sets out the skills and experience needed to do the job. In practice, many employers combine both into one advert, but it’s still worth keeping ‘work’ and ‘requirements’ separate.
How do I stop getting irrelevant applications?
Make the first 10 lines specific, especially the outcome, must-haves, location and pay band. Most irrelevant applicants are responding to vague ads that sound like they could be anything.
Sources Consulted
Disclaimer
This article is for information only and does not constitute legal, HR or financial advice. For advice on your specific situation, consult a qualified professional and refer to current UK guidance.
