Cursor Tab is the most frequent form of interaction with the model and at the same time the most underrated in risk. It offers not a single line but multi-line changes, jumps within the file and continuations that reach into another file. Tab accepts the suggestion, Esc or continued typing rejects it, and a separate shortcut accepts only the next word. After an acceptance the editor may offer to jump to the next point of change - and this is where the difference between work and momentum begins: the jump sets your next step for you, and you agree to it with the same gesture you used for the previous one.
The naive attitude to Tab is simple: it is autocomplete, you are used to pressing it, so press it. On short obvious continuations that is true, and the cost of a mistake is near zero. But the same gesture also accepts a twenty-line block that changes error handling or a function's contract. The hand has already learned to press while the eye has not yet read - and an edit nobody reviewed appears in the code. One key for actions of very different cost is the tool's defining property: it saves motions and for exactly that reason erases the line between a small decision and a large one.
It breaks on the mismatch between the cost of checking and the size of the suggestion. While the suggestion is local and syntactically obvious, checking takes a fraction of a second. As soon as it moves into business logic, security or data migrations, the cost of what went unread jumps: a mistake in such an edit is found not by the compiler but by a user. The difference here is not the volume of code but who notices the mistake and when. Hence the simple rule - the further a suggestion is from local syntax, the closer its review should be to a full one.
It helps to lay the situations and the actions out in a table once: what to do with an obvious continuation, with a large block, with a wrong idea, when you need only one word, and when the suggestion leads into another file. You come back to it while the reflex is still forming: what needs training is not the speed of the keystroke but the habit of reading first and accepting second.
| Situation | Action | Why |
|---|---|---|
| An obvious continuation of the line | Accept | The cost of checking is minimal |
| A large multi-line block | Read the whole suggestion first | It may change a contract or error handling |
|---|
| The wrong idea | Esc or keep typing | Do not train yourself to accept out of inertia |
|---|
| Only one word is needed | Accept the next word | Control over the wording stays with you |
|---|
| A jump into another file | Look at where it leads and what surrounds it | The continuation widens the diff |
|---|
Tab has a limit of applicability, and it is worth stating. Tab works from what is already written - it continues a form rather than carrying out an intent. While the intent is readable from the surrounding code, that is convenient and fast. As soon as the task requires a decision that is not yet in the text - choosing an approach, touching several places coherently, changing behavior - the suggestions start offering the plausible continuation instead of the needed one. The sign that it is time to stop pressing and state the task in words is simple: you have rejected the suggestion three times in a row because it is not about the right thing.
Cross-file jumps deserve particular caution. A continuation in a neighboring file looks exactly like a continuation in the current one, but it extends the diff into a place you are not looking at right now. Before accepting, make sure you understand where the jump leads and what surrounds it there: otherwise the change spreads through the tree unnoticed by its own author.
There is a flip side that gets discussed less often. Rejecting a suggestion is not a refusal of the tool but part of working with it. Continuing to type rejects the hint just as reliably as Esc and costs no extra motion. Accepting only the next word is especially useful when the idea is right and the wording is yours: you take what is useful without handing over control of the rest of the line.
In real work you learn about what you accepted too much from the diff, not from a feeling. After a session with suggestions active it is worth reviewing the changes file by file rather than by the editor's last screen: that is where it becomes visible that an edit reached a neighboring file, that an error handler you never wrote arrived alongside the line you wanted, or that a rename went further than you thought. The sign is recognizable - the diff contains lines you do not remember. They are not excused on the grounds that the code looks reasonable: an unread edit stays unread even when it is correct.
The engineering conclusion is less about Tab than about habit. A tool that guesses the intent nine times out of ten trains you not to check the tenth - and that tenth costs more than all nine saved seconds. The discipline here is cheap: read the ghost text in full whenever it is longer than a line, and never accept out of momentum. In places where every edit requires review, it is easier to turn the suggestions off than to fight your own reflex each time.
The typical failures with Tab are predictable. Accepting a multi-line block without reading it and getting a changed contract or changed error handling. Agreeing to a continuation in another file without looking at what surrounds it. Keeping suggestions on in places where every edit requires review. And training yourself to press Tab automatically - at which point the tool stops being an assistant and becomes a source of edits nobody reviewed.