What should an NDA cover if I'm sharing a trade secret with a potential Ontario business partner?

A non-disclosure agreement protecting a trade secret should start by clearly defining what counts as "confidential information" — broadly enough to cover the actual secret, whether that is a formula, process, customer data, pricing, or source code, but specific enough that both sides understand what is protected. It should state the permitted purpose for which the recipient can use the information, such as evaluating a potential deal, and expressly prohibit any other use, including reverse-engineering or sharing with anyone outside the recipient's own team without consent.

Because trade secrets have no registration system, an NDA is often the main evidence that information was actually treated as confidential if you ever need to bring a breach-of-confidence claim, so it should also require reasonable security measures and return or destruction of the information if the deal does not proceed. A well-drafted NDA also addresses duration, since confidentiality obligations often need to survive well beyond the negotiation itself, what happens to any work product created using the information, and carve-outs for information the recipient already knew or that becomes public through no fault of theirs. Having a lawyer review the NDA's scope before sharing anything genuinely sensitive is worth the modest upfront cost.