The person at your door came in with the weather

• They offer to run your insurance claimThis is the clearest one, because it is not a judgement call. RSMo 407.725 bars a Missouri roofing contractor from representing or negotiating on a homeowner's behalf on an insurance claim, so an offer to handle your claim is an offer to do something the statute forbids. A company that does not know that, in a state where hail is the entire business model, has not read the rules governing its own trade.
• They offer to do something about your deductibleMissouri law bars a contractor from advertising or promising to pay your deductible, to absorb it, or to rebate any part of it, so an offer to cover your deductible is an offer to break RSMo 407.725. It is also, in effect, an invitation to misstate the loss to an insurer, with your name on the paperwork rather than theirs.
• The paperwork is an authorisation rather than a contractRead what you are being asked to sign. If the document does not contain a price, and instead authorises the company to do whatever work is eventually approved, you have not agreed to a job, you have agreed to a company. Ask for a scope and a number.
• The offer expires when they leaveRoofs are not perishable goods. A discount tied to signing today is a technique, and the reason it exists is that comparison is the enemy of the sale.
• No local address, or an address that is a mailboxPut the address into a map and look at it. Storm operations open temporary offices and close them. Neither a shared office nor a small one is disqualifying, but a company with nowhere to be found is a company you cannot find when a valley leaks.
• Out-of-state plates and a rented truckNot proof of anything on its own. Combined with anything else on this list, it is a strong signal about where this company will be next season.
• They found damage you cannot see and will not photographAsk for the photographs of your own roof, on your own phone, before they leave. A reluctance to hand over images of hail bruising is worth taking seriously, and so is damage that appears only in a verbal description.
• They want to go on the roof before you have agreed to anythingAn inspection is fine and normal. An inspection by somebody you did not call, on a roof that was not leaking, an hour after a storm, is a different transaction. Roof damage that was not there before the visit is a recurring complaint in this market and a hard one to prove either way.
• Large money up frontMaterials do not need to be paid for by you before they are delivered. A deposit is normal. A deposit that resembles the whole job is financing somebody else.
• The company name is new and the reviews are newerCheck the dates on the reviews, not the count. Twenty reviews all posted inside one month, on a business with no history before that month, is a pattern rather than a coincidence.
• Nobody will tell you who is doing the workAsk who the crew is and whether they are employees. In storm season, the answer is sometimes a crew hired that week from three states away, which is not automatically bad work and is automatically nobody you can call later.

What a legitimate storm conversation sounds like

It is much less exciting. The contractor inspects, photographs, measures, and gives you a written scope of work with a price. If you have a claim, that document is yours: you file, you correspond, you decide. The contractor may be present when the adjuster comes out, as the contractor doing the work, and may point at the physical roof and explain what is being priced. That is the whole of the lawful role in Missouri and it is a genuinely useful one.

Everything more than that belongs to somebody else. If you actually want a representative arguing your position with the insurer, that is a public adjuster, licensed under Missouri chapter 325. They charge a fee, that fee is not capped by statute, and RSMo 325.055 stops them from also doing the repair work. Whether that trade is worth it is a real question with real answers on both sides. It is not a question a roofer can answer for you.

The two questions that end the conversation early

Can you send me a certificate of insurance directly from your agency, and can you leave me a written scope with a price before I sign anything?Ask both at the door

Neither is aggressive, both are ordinary, and both take a legitimate company about a day. The answer to those two questions sorts this market faster than any ranking, including the one on this site.