I'm not sure what you want to disable exactly but you should look at eglot-ignored-server-capabilities
:
For example to disable inlay hints: (setq eglot-ignored-server-capabilities '(:inlayHintProvider))
.
Here is the complete list of server capabilities:
(const :tag "Documentation on hover" :hoverProvider)
(const :tag "Code completion" :completionProvider)
(const :tag "Function signature help" :signatureHelpProvider)
(const :tag "Go to definition" :definitionProvider)
(const :tag "Go to type definition" :typeDefinitionProvider)
(const :tag "Go to implementation" :implementationProvider)
(const :tag "Go to declaration" :declarationProvider)
(const :tag "Find references" :referencesProvider)
(const :tag "Highlight symbols automatically" :documentHighlightProvider)
(const :tag "List symbols in buffer" :documentSymbolProvider)
(const :tag "List symbols in workspace" :workspaceSymbolProvider)
(const :tag "Execute code actions" :codeActionProvider)
(const :tag "Code lens" :codeLensProvider)
(const :tag "Format buffer" :documentFormattingProvider)
(const :tag "Format portion of buffer" :documentRangeFormattingProvider)
(const :tag "On-type formatting" :documentOnTypeFormattingProvider)
(const :tag "Rename symbol" :renameProvider)
(const :tag "Highlight links in document" :documentLinkProvider)
(const :tag "Decorate color references" :colorProvider)
(const :tag "Fold regions of buffer" :foldingRangeProvider)
(const :tag "Execute custom commands" :executeCommandProvider)
(const :tag "Inlay hints" :inlayHintProvider)