remove syntaxTree from docs
diff --git a/docs/book/src/contributing/lsp-extensions.md b/docs/book/src/contributing/lsp-extensions.md
index 1ada1cb..8c06f33 100644
--- a/docs/book/src/contributing/lsp-extensions.md
+++ b/docs/book/src/contributing/lsp-extensions.md
@@ -694,24 +694,6 @@
Cancels all running flycheck processes.
-## Syntax Tree
-
-**Method:** `rust-analyzer/syntaxTree`
-
-**Request:**
-
-```typescript
-interface SyntaxTreeParams {
- textDocument: TextDocumentIdentifier,
- range?: Range,
-}
-```
-
-**Response:** `string`
-
-Returns textual representation of a parse tree for the file/selected region.
-Primarily for debugging, but very useful for all people working on rust-analyzer itself.
-
## View Syntax Tree
**Method:** `rust-analyzer/viewSyntaxTree`
