Your boss is not a mind-reader.

Which is great, or else they'd find out how you really felt about that last assignment.

But the flip side is that your boss can't simply intuit your career ambitions — meaning it's on you to tell them that you want a promotion and/or a salary bump.

That's not necessarily an easy conversation to have, but it's a key one, at least according to Toni Thompson.

Thompson has spent 11 years in human resources; she's currently the head of human resources and talent at The Muse, which is a job search and career advice site.

When she visited the Business Insider office for a Facebook Live interview in June, Thompson mentioned three ways to get ahead in your career. "Stay engaged and be hard-working," she said.

"Also talk about what you want with your boss. Make sure that they know what salary you want eventually and the title you want or more opportunities that you want."

Thompson added:

"They may not be able to give it to you right away. But it's really great if you have that conversation upfront because then they are able to tell you … are you ready for the role that you're saying you're ready for? And they'll be able to keep an eye out for big assignments or responsibilities that they might be able to give to you.

"And also, when they're in that conversation with the CFO and they have an opportunity to ask for more money for you, they'll take it because they know that it's important for you."

In other words: Your boss probably has the resources to prepare you for the responsibilities you want. But they need to know what it is you want.

In her experience, Thompson said, only about half of people take the initiative to have these conversations with their boss. But everyone should be doing it.

Of course, if you're at the point where you're asking your boss for a raise or a title change in the immediate future, you've got to explain why you deserve it. Thompson said you should know "what value you're bringing to your boss, your company, your team, and what you've accomplished since the last time you had an increase."