What AI Writing Tools Get Wrong (and How to Catch It Before You Hit Send)

Browsy’s six writing tools are useful precisely because they’re good most of the time — good enough that it’s tempting to select text, click a tool, glance at the result, and hit Replace without really reading it. That habit works fine for a while, right up until it doesn’t. This post is about the specific ways these tools fail, because “AI can make mistakes” is true but not actionable — knowing which mistake a given tool is prone to is what actually lets you catch it.

None of this is a Browsy-specific problem. It’s inherent to how large language models generate text, and it applies to every AI writing tool, not just this one. But the six tools covered in the field guide each optimize for a different job, and that means each one fails in a different, fairly predictable way.

Expand: the one that can invent things

Expand’s job is to add detail and context to a sparse sentence. That’s also exactly why it’s the riskiest tool of the six: to add detail that wasn’t in your original text, the model has to generate something new, and “something new” from a language model is not the same as “something true.”

Feed Expand a terse note like “met with the vendor, pricing came up” and it might return a paragraph that includes a specific dollar figure, a meeting length, or a follow-up date — details that read naturally but that you never provided. The model isn’t lying; it’s doing what a language model does when asked to add plausible-sounding content, which is generate the statistically likely continuation, not consult a fact it verified. If the number happens to be wrong, there’s nothing in the tool that would know that.

The check: treat anything Expand adds — as opposed to detail you already wrote and it merely reworded — as a claim, not a fact. Numbers, names, dates, and quantities are the specific things to scan for, because they’re the details a reader is most likely to take at face value and the ones most costly to get wrong.

Make Concise: the one that can drop what matters

Make Concise is built to remove words without losing points, which works well for redundant phrasing and rambling structure. Where it struggles is with qualifiers that look removable but aren’t — “in most cases,” “as of last quarter,” “for accounts opened after March” — because a hedge or a scope limiter often reads, to a length-optimizing pass, like the least essential part of the sentence.

This matters most in exactly the writing where hedges carry real weight: a compliance note, a medical description, an estimate you gave a client with explicit caveats attached. Losing “for accounts opened after March” from a sentence doesn’t shorten the meaning — it changes it, silently, in a way that looks identical to a normal edit.

The check: for anything with a qualifier, a date range, or a scope limiter, compare the shortened version against the original clause by clause rather than reading it as a whole. If a caveat is gone, that’s not concision — that’s a different claim.

Adjust Tone and Translate: the ones that don’t know your audience

Tone and Translate both take a second input beyond the text — a target tone or a target language — but neither one knows anything about the specific person who’s going to read the result. A tone shift to “formal” is a reasonable statistical guess at what formal sounds like in general; it isn’t calibrated to the specific colleague who finds over-formality stiff, or the client relationship where “formal” would read as a change in temperature they’ll notice and wonder about.

Translate has a sharper version of the same problem: idiom, humor, and culturally specific references often don’t have a clean equivalent in another language, and a translation tool will usually produce something fluent-sounding rather than flagging that the original doesn’t translate cleanly. A joke, a regional turn of phrase, or a reference that only lands in the source culture can come back as grammatically correct text that means something flatter, or subtly different, than what you wrote.

The check: for anything routine, a fluent-sounding result is good enough. For anything that matters — a message going to a specific person you know well, a translation going out under your name to a professional contact — read it as that person would, not just for correctness. If you speak any of the target language yourself, or know someone who does, a translation worth getting right is worth a second set of eyes before it goes out, the same way you’d want a second read on anything consequential you wrote yourself.

Fix Grammar and Rewrite: the ones that can overwrite intent

These two are the narrowest tools of the six, and they’re also the ones most likely to quietly undo a choice you made on purpose. Fix Grammar can flag a sentence fragment used for rhythm, a regional or informal construction, or a piece of technical jargon as an error and “correct” it into something more conventional but less like your voice. Rewrite goes further — it restructures for clarity, which occasionally shifts emphasis in a way that changes what the sentence is actually claiming, not just how it’s phrased.

Neither failure is common, and both tools are explicitly scoped to avoid this — Fix Grammar in particular is built to leave your voice alone. But “usually careful” isn’t “never wrong,” and the failure mode when it happens is specifically that the result reads more polished, which makes it less likely you’ll stop and question it.

The check: if a result feels smoother but something in it doesn’t sound like what you meant to say, trust that instinct over the polish. It’s worth rereading a rewritten sentence and asking “is this still my claim” before asking “does this sound better.”

Why the streaming preview is the actual safety mechanism

Every one of Browsy’s tools works the same way once you click one: the result streams into a preview, token by token, and nothing in your document changes until you click Replace. That two-step design — generate, then a separate explicit accept — is described in more detail in Privacy by Architecture, but it’s worth calling out here specifically as the mechanism that makes everything above catchable in the first place.

The failure mode isn’t the tools generating an occasional bad result — every AI writing tool does that sometimes. The failure mode is skipping the read between generation and acceptance, which turns a catchable mistake into a sent one. The preview step exists so you don’t have to trust the model; you just have to actually look before you click.

Matching scrutiny to stakes

You don’t need to fact-check every AI-assisted Slack message with the same rigor you’d apply to a contract clause, and treating every rewrite as equally risky is its own kind of friction that defeats the point of using these tools at all. A rough calibration:

• Low stakes, low scrutiny: internal chat messages, casual notes, first drafts you’ll revise again anyway. A glance at the preview is enough.
• Medium stakes, read it once: client emails, comments on shared documents, anything going to someone outside your immediate team. Read the full result, not just skim it.
• High stakes, verify specifics: anything with numbers, dates, legal or medical language, or a translation going out under your name. Check every fact Expand added, every qualifier Make Concise might have dropped, and consider a second read from someone who knows the context — or the language — before it ships.

The tools don’t know which category a given piece of text falls into. That judgment call is still yours, and it’s the one part of the process no AI writing tool — Browsy included — is trying to take away from you.

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None of this is an argument against using AI writing tools — it’s an argument for reading what they give you, which the streaming preview is specifically built to make easy. If you’re new to Browsy’s toolset, the field guide to all six tools is the place to start; if you’re deciding whether a BYOK tool is worth trusting with this kind of text at all, What Is BYOK covers what does and doesn’t leave your browser in the first place.