Steps to reproduce:
1. Create new Unity project using Universal 3D Template
2. Open Package Manager window
3. Find and Install “Splines” package
4. Once installed right-click in Hierarchy window > Splines > and create Square
5. In Inspector > Spline Container expand “Int Data”
6. Press “+” to add data to the list
7. In Element 0 > Key add a longer text (for example: NewNameNewNameNewNameNewNameNewNameNewNameNewNameNewName)
8. Observe the Inspector window

Actual results: “Key” field doesn’t have character limit, allowing to add long text breaks Inspector UI
Expected results: “Key” field has character limit, longer text is truncated and doesn’t break Inspector UI

Reproducible with versions: 2.8.2 (6000.0.59f1, 6000.2.7f1, 6000.3.0b4, 6000.4.0a1)

Tested on (OS): Windows 11, macOS Silicon, Tahoe 26.0 (M1)