A clause-by-clause read of the parts courts actually test: duration, geography, the definition of competition, consideration, choice of law and forum.

The document is usually four pages, and about a page and a half of it matters. Everything else is recitals, severability boilerplate, and the assignment language that lets a buyer inherit the promise you made. A careful read means finding the handful of clauses a judge would actually weigh, marking them, and writing next to each one what it would take to enforce it against you specifically. That is a different exercise from asking whether the agreement is fair, and it is the only one that produces answers you can act on.
Read the number, then read what it attaches to. A twelve-month restriction running from your last day of employment behaves very differently from one running from the last date you received any payment, or from the date of a final judgment enforcing the covenant, a drafting move that makes the clock restart if you litigate and lose. Look also for tolling language, which pauses the period during any breach, meaning a single month of arguable violation can add a month to the tail. Short and fixed survives. Open-ended, self-extending, or tied to events the employer controls draws scrutiny.
Then ask whether the duration matches anything real. Courts generally want the period to correspond to how long the protected information stays valuable, or how long it takes a successor to rebuild a client relationship. If your industry reprices quarterly and your pipeline data goes stale in ninety days, a three-year term is doing something other than protecting a legitimate interest, and that gap is the first thing a good attorney will point at. Write down, in your own words, how long your knowledge would actually be useful to a competitor.
The traditional form names a radius or a list of counties and states, and its weakness is usually overreach: a fifty-mile radius from every office the company operates, including the eleven you have never visited. What holds up tends to be narrow and tied to your own footprint, the territory you actually covered, the accounts you actually touched. Increasingly, though, the clause has no map in it. Instead it restricts you from serving any customer or prospect of the company, anywhere, which converts a geographic limit into a customer limit and can be broader in practice than a statewide ban.
This is the clause most worth copying into a separate document and reading on its own. Some definitions are functional and survivable: a business that provides the specific services you personally provided during your final twelve months. Others sweep in any entity engaged in any line of business the company conducts or plans to conduct, which would cover a firm whose only overlap is a product division on another continent. The pattern is consistent. Definitions anchored to your own role and recent work tend to be enforced as written; definitions anchored to the employer's entire corporate ambition tend to be narrowed or struck.
Find out what you received, and when. A covenant signed as a condition of a job offer, before you started, is on different footing from one presented in year six with no raise attached and continued employment as the stated exchange. Several states treat continued at-will employment as sufficient; others require something independent, a signing payment, a promotion, access to genuinely confidential material, equity that vests. Check the date on the signature page against your offer letter and your pay records. If the covenant arrived alone, unaccompanied by anything new, that is a fact worth writing down before you forget the sequence.
These two clauses often decide the outcome before anyone reaches the merits. An agreement specifying Delaware law and exclusive jurisdiction in Delaware courts, signed by someone who has worked only in Oakland, sets up a fight about whether the chosen state's rules or the employee's home state's public policy governs, and several states have statutes that void the choice outright for resident employees. Read the fee-shifting provision in the same sitting, since a one-way clause awarding the employer its attorney fees changes the arithmetic of resisting. The Federal Trade Commission is responsible for competition policy touching these agreements at the national level, and the state-by-state variation sits underneath that.
Do this with a pen, in one sitting, and take the marked copy to counsel rather than the clean one. The annotated version tells a lawyer in ten minutes what a narrative email cannot, and it makes the first consultation about strategy instead of transcription.
A tolling clause pauses the restricted period during any alleged breach, so a disputed month can extend the restriction by a month. It is short, easy to skim past, and materially changes how long you are bound.
Some agreements measure the restricted period from the date a court enforces the covenant rather than from your last day of work. That drafting makes litigating the clause costly even if you eventually settle.
Clauses that draw a radius around all company locations, including sites you never worked at, are a common form of overreach. Narrower language tied to your actual territory is far more likely to be enforced as written.