lsp-inlay-hint-mode
lsp-inlay-hint-mode: per-buffer gate for textDocument/inlayHint — turn it off and inlay hints disappear from this buffer.
A feature gate, one of the set lsp-mode turns on for you. It carries no keys and no options of its own; what it decides is whether this buffer talks to its language server about textDocument/inlayHint — the request behind inferred types and parameter names shown inline.
Why it is a mode rather than a setting
Because it is per buffer, and because it composes. lsp-mode implies the whole set, so attaching a server switches them all on together; turning one off afterwards is a normal mode toggle rather than a special case in the LSP client:
:lsp-inlay-hint-mode
Toggling it off means inlay hints disappear from this buffer. Nothing else about the attachment changes — the server stays running, and every other feature keeps working.
That is the point of splitting the umbrella into gates. A server that is excellent at completion and slow at inlayHint can be kept, with the slow part switched off for the buffers where it hurts.
Options
None. The mode's presence is the setting.
Keybindings
None of its own.