A museum label is short, clear, and respectful. 

The 90-word label template

Sentence 1 (object ID): what it is + key material/technique (simple)
Sentence 2 (what you see): decoration layout + motifs
Sentence 3 (meaning hypothesis): cautious interpretation (may suggest…)
Sentence 4 (context question): one research question for next steps

Example label (approx. 90 words)

“This vessel is a glazed ceramic jar with blue painted decoration. I observe a banded layout with a main dragon motif and cloud fillers, framed by geometric borders. The repeated dragon imagery may suggest themes of authority or protection, though meanings depend on period and context. The stable foot ring and controlled band spacing suggest planned production and careful finishing. Research question: in museum collections, how do similar dragon-and-cloud jars differ in border style and foot treatment?”

Now read an article about labelling a metal or ceramic object.