What does it mean that provide context when communicating?

Always give your audience the context they need to interpret your message correctly.

Example: You send a Slack message: 'We should switch to Postgres.' Your teammate reads it and thinks you're proposing a migration of the entire production database this quarter. You meant the new microservice that hasn't launched yet. The instruction was clear. The context was missing. Now you're spending 45 minutes in a meeting that didn't need to happen — because you assumed they knew what you were referring to.

Try this: Pick a message you sent in the last week — an email, Slack message, or document. Reread it as if you know nothing about the project, the conversation history, or your intent. Identify every assumption the reader would need to already hold for the message to land correctly. Rewrite it with those assumptions made explicit. Compare the two versions. The difference is the context you failed to provide.