Start from your workflow, not their demonstration
A demonstration is built to succeed. It uses clean data, a cooperative example, and a path the presenter has walked many times. The useful evaluation runs the other direction: bring your own material. Your actual drawings, your actual specification section, a real message thread from a difficult project, with confidential details removed.
How a vendor responds to that request is itself informative. Ones who welcome it usually have a product that holds up. Ones who steer you back to the prepared path usually do not.
Ask the questions that determine long-term cost
Who owns the data you put in, and can you export all of it in a usable format if you leave. What happens to your content in terms of storage, processing location, and whether it is used to improve models. Which integrations are actually supported today, for the platform and license tier you hold, as opposed to on a roadmap. What the total first-year cost is including implementation, and what renewal pricing looks like.
Get answers in writing. Verbal assurances during a sales process carry no weight eighteen months later when the relationship has changed hands twice.
Test whether they understand contracting
Construction has specifics that generic software teams miss consistently. Retainage. Progress billing against a schedule of values. Change order approval sequences. Flow-down terms. The distinction between a pending, approved, and billed change. Lien rights and notice deadlines. Prevailing wage and certified payroll where applicable.
Ask how their product handles a few of these in detail. A vendor who understands why an approved change order is not the same as a billed one has built for contractors. One who has to check will need you to explain your business to them throughout the implementation, and you will be paying for that education.
Plan the exit before you sign
Assume the relationship ends. Vendors get acquired, change direction, raise prices, or simply stop fitting how you work. Before committing, establish how you would get your data out, what format it would arrive in, how long the contract obligates you, and what would be irreplaceable if the service disappeared.
Prefer arrangements where your data remains in systems you control and the vendor connects to it, rather than ones where your operating history lives inside a platform you cannot extract it from. That single preference determines how much leverage you have in every conversation that follows, including the ones about price.
Ask what happens when it is wrong
Every system that classifies, extracts, or drafts will produce incorrect output sometimes. The meaningful question is not the stated accuracy rate but what the product does about it: whether confidence is exposed so uncertain items can be routed for review, whether corrections improve future results, whether there is an audit trail showing what was generated versus what a person changed.
A vendor who discusses error handling in specifics has thought seriously about deployment in a business where mistakes carry contractual consequences. One who responds only with accuracy percentages has been selling to people who never asked the follow-up question, and you will be discovering the answer yourself in production.