For purposes of general writing, it’s best to be wary of using the passive voice. That’s even more the case when it comes to contracts. To quote MSCD 2.17:
There are three drawbacks to using the passive voice. First, using the passive voice and including a by-agent unnecessarily adds a couple of extra words. Second, using the passive voice and omitting the by-agent obscures who the actor is. And third, the passive voice disrupts the normal subject-verb-object order of a sentence. Those drawbacks apply to any form of writing, but in contract prose, the stakes are particularly high—the consequences of obscuring who the actor is can be drastic. So in contract prose, you should always use the active voice unless it’s clear that the passive voice represents an improvement.
MSCD 2.18 provides as an example of appropriate use of the passive voice If any Necessary Project Approval is revoked. If various organizations might revoke an approval, it would be counterproductive to insist on the active-voice version, If any Person revokes any Necessary Project Approval.
Here’s another example one of my Penn Law students recently pointed out to me: After the Closing Acme will remain bound by article 6 of the Shareholders Agreement. Yes, that’s in the passive voice, but I don’t see any point in saying instead After the Closing article 6 of the Shareholders Agreement will continue to bind Acme. The reader is more interested in Acme than in article 6 of the Shareholders Agreement, so it’s appropriate to put Acme first.