The list that decides the year
A recruitment desk lives or dies on which companies it decides to call. Get that list wrong and every downstream improvement, better sequences, better copy, more activity, is optimisation on top of a bad premise.
Most target lists are built from whoever came up in conversation, plus whoever is advertising. The first is biased towards the loud, the second is biased towards the desperate, and neither describes the market.
What the tiers are for
Tier A is verified. Somebody, in this case your agent, actually looked at the company and can show you why it fits. These are worth researched, personalised outreach.
Tier B is likely. The firmographics match and the judgement call was positive, but nobody checked. Fine for a sequence, not worth a bespoke approach until one of them replies.
Tier C is possible. Keep it, do not work it. It is where you go when tier A is exhausted or when the market shifts.
The tiers exist so effort is proportionate to confidence, which is the difference between a list you work and a list you own.
What you get back
A CSV of companies with tier, evidence, and the firmographics that were actually used to judge them. Above it, the market size: how many companies exist that match your hard filters at all, and what share of them you are looking at. That number is what turns a prospect list into a plan.
Variations worth knowing
Derive the profile from wins, not from ambition. Give it your five best clients by margin, not the five logos you most want. The derived profile will be less flattering and considerably more useful.
Add a technology filter. If the companies you win share a stack, a payroll system or a specific platform, that is often a sharper qualifier than industry classification.
Layer a hiring signal on top afterwards. Once the list exists, watch it for the moment a company starts hiring in your discipline. That is find every company hiring for your specialism this week, and it is how a static list becomes a working pipeline.
Where this goes wrong
An empty page is not a zero. A provider that is unavailable returns nothing, which looks the same as a market with no companies in it. The play distinguishes the two rather than reporting an outage as a market finding.
Industry classification is unreliable. Half the companies in any database are filed under something approximate. That is why the reverse people search exists: what a company employs is a better description of what it does than what it is classified as.
Verifying everything. The verification step is the expensive one. Running it across the whole list instead of the borderline cases turns a proportionate spend into a large one for very little extra accuracy.