Specify base url is path replacement

Co-authored-by: Justin Spahr-Summers <[email protected]>

Author: allenzhou101

docs/specification/draft/basic/authorization.md

@@ -121,8 +121,7 @@ For example: `MCP-Protocol-Version: 2024-11-05`
 #### 2.3.2 Authorization Base URL
 
 The authorization base URL **MUST** be determined from the [SSE
-endpoint]({{< ref "specification/draft/basic/transports#http-with-sse" >}}) URL by
-preserving only the `scheme`, `hostname`, and `port` (if non-standard). For example:
+endpoint]({{< ref "specification/draft/basic/transports#http-with-sse" >}}) URL by discarding any existing `path` component. For example:
 
 If the SSE endpoint is `https://api.example.com/v1/sse`, then: