A script is a fixed sequence of steps: scrape a page, send an email, update a spreadsheet, in that order, every time. The moment something outside its assumptions shows up, it breaks. A page's layout changes. An API returns an error nobody coded for. A reply doesn't fit the yes or no the script expected. When that happens a script either stops cold or keeps going and does the wrong thing quietly, and nobody notices until a report comes up empty or a lead sits ignored for weeks.
An agent works from a goal instead of a fixed script. It looks at the actual state of things, decides what to do next, acts through the same tools a person would use (a browser, an email account, a database, an API), then checks whether that action actually worked before moving on. If it didn't work, it tries a different approach or flags it for a person instead of pretending everything is fine. That loop, read, decide, act, check, retry or escalate, is what lets something run unattended for months instead of needing someone to babysit it. We run that pattern across our own operation: 110+ scheduled jobs going 24/7 across 40+ live integrations, 88 systems in production, content going out in 7 languages. None of that holds together on scripts alone; something has to notice when a job's output looks wrong and decide what to do about it.
None of this means an agent should decide everything. A judgment call with real stakes, a customer complaint that needs tact, a decision that cannot be undone, a brand call your team would want to weigh in on, should route to a person, and we build that handoff in on purpose rather than let the agent guess. Before we build anything we map the manual work as it actually happens today and say plainly which parts a system can take on and which still need a person. If your process is small enough that one person already catches every exception by feel, or the stakes are high enough that nothing should move without a person first, that's a case for a script, or no automation at all, not an agent.