A museum label frequently gives a name, a date, a material and little else. The brevity is the result of hard constraints rather than an assumption about the visitor.
Reading time is the binding limit
Visitors spend a short and fairly consistent period in front of each object, and much of that is spent looking rather than reading.
A label longer than that period will be abandoned mid-sentence, which is worse than a shorter one because it leaves the reader with a partial idea.
Museums therefore write to a word count derived from observed behaviour, and the count is smaller than most people assume.
Physical constraints shape the text
Labels must be legible at a distance that allows several people to stand near an object without blocking each other, which sets a minimum type size.
That size, combined with the space available beside the object, produces a maximum number of words before the text is even written.
Cases, mounts and conservation lighting all limit where a label can be placed, and the object always takes priority over the panel.
Curatorial caution removes claims
Attributions, dates and provenance are frequently uncertain, and museums are reluctant to state as fact anything that current scholarship treats as contested.
Hedged language takes more words than a plain claim, so cautious statements are often reduced to a bare minimum instead.
This is why labels use formulations such as attributed to or workshop of, which look like brevity but are actually precision.
The interpretation has moved elsewhere
Detailed context now lives in room panels, printed guides, audio commentary and online collection records, each aimed at a different level of interest.
Splitting the material this way lets a visitor choose depth rather than forcing one length on everyone, which the wall label cannot do.
Online catalogue entries in particular often contain far more than any label could, including bibliography and conservation history.
How to get more from a gallery
Room-level panels usually explain why the objects are grouped as they are, which is the information that makes individual labels intelligible.
Asking gallery staff is more productive than most visitors expect, since many are trained specifically to answer questions about the objects in their rooms.
Where an object is genuinely interesting, the collection database entry is usually the fastest route to the detail the label had no room to carry.