Reading someone else's code almost always begins with a single unclear name: a function, a variable or a class whose purpose does not read off its signature. A standard hover card shows the type and the signature but does not answer "what does this do and why is it here". DeepWiki closes exactly that gap: hover over the symbol, press Cmd+Shift+Click, and get an explanation built with the whole repository in view, not a single line.
The naive move is understandable and nearly inevitable: read that explanation and take it as a fact about the code. Since it is coherent, refers to neighboring functions and sounds confident, it seems logical to build the next decision on it - call the symbol, change it, rely on the described contract. It saves time: no need to go to the definition and work it out yourself.
It breaks where the explanation is taken for proof. DeepWiki is generation on top of retrieved context, not an analysis by the compiler. In one paragraph, statements directly backed by code ("the function takes these arguments") sit next to the model's inferences about intent ("probably used for caching"), indistinguishable in tone. For a quick orientation the difference does not matter; for critical behavior it is decisive.
The professional technique is to split the explanation into two layers and ask about each: "which statements are backed by the code and which are inference?". The first are verifiable at once - by going to the definition, the list of callers, the tests and the git history. The second stay a hypothesis until you have seen them in the code with your own eyes. In practice it looks like this: after reading a paragraph, note to yourself what here can be pointed at with a finger in a line of code and what is only a plausible guess about behavior; the first is closed in a minute, the second demands a real check. Here DeepWiki is accelerated navigation to the right places, not a replacement for reading them.
Why the tool is built as navigation rather than a source of truth. The model sees retrieved fragments, not the whole system, and does not execute the code; it guesses a symbol's role from its surroundings well but does not guarantee it. This is a deliberate trade: an instant plausible explanation instead of a slow but exact conclusion from the definition and the callers. As long as you use it as a compass, the trade pays off; the moment you take it for a map of the terrain, it starts to mislead.
The mechanism for passing the explanation onward is worth knowing. From the DeepWiki panel the explanation can be sent into the agent's context through the menu in the corner of the panel and then @-mentioned in the conversation. This is convenient, but it also multiplies the risk: an unverified inference that reached the agent's context then looks like an established fact both to you and to the model that builds edits on it.
The cost of ignoring the layers is concrete. Taking the assumption that "this function is thread-safe" or "the resource is released here" for a fact - and building a change on it - means introducing a bug that was not in the source, yet now rests on a nicely worded description. And such a bug is especially persistent because it looks justified: under it lies a coherent explanation easy to mistake for design documentation, though it was only the model's guess. The radius of the error grows with the symbol's criticality: an entry point, money handling, releasing a resource.
DeepWiki is justified where the goal is understanding and speed, not an irreversible decision. A first pass into an unfamiliar module, a quick map of who is tied to whom, recovering the author's intent - here the explanation saves hours. A good habit is to keep DeepWiki open exactly during the reconnaissance phase and to close it the moment editing begins: that way the explanation helps you orient yourself but does not quietly turn into the ground for an edit. The moment you move to editing critical behavior, the weight of proof shifts from the explanation to the definition, the callers and the tests.
You should check the result of working with DeepWiki by a simple criterion: can you point to a place in the code for every statement you rely on. For non-critical reading the explanation itself is enough. For anything that goes into an edit - the definition, the callers, the tests and, when in doubt, the change history. If there is no line of code under a statement, it is a hypothesis, and it must be handled as a hypothesis.
The typical failure is quietly promoting an explanation from "seems so" to "is so" without going to the code. The sign is simple: an edit is justified by a phrase from the DeepWiki panel rather than a line of the definition or a failing test. Find the confirmation in the code first - in most cases it is right there, and then the explanation did its job: it brought you to the right place faster than a manual search.