Merge branch 'main' into patch-1

Author: xyc

docs/docs/concepts/tools.mdx

@@ -213,6 +213,18 @@ When implementing tools:
 9. Consider rate limiting for resource-intensive operations
 10. Log tool usage for debugging and monitoring
 
+### Tool name conflicts
+
+MCP client applications and MCP server proxies may encounter tool name conflicts when building their own tool lists. For example, two connected MCP servers `web1` and `web2` may both expose a tool named `search_web`.
+
+Applications may disambiguiate tools with one of the following strategies (among others; not an exhaustive list):
+
+- Concatenating a unique, user-defined server name with the tool name, e.g. `web1___search_web` and `web2___search_web`. This strategy may be preferable when unique server names are already provided by the user in a configuration file.
+- Generating a random prefix for the tool name, e.g. `jrwxs___search_web` and `6cq52___search_web`. This strategy may be preferable in server proxies where user-defined unique names are not available.
+- Using the server URI as a prefix for the tool name, e.g. `web1.example.com:search_web` and `web2.example.com:search_web`. This strategy may be suitable when working with remote MCP servers.
+
+Note that the server-provided name from the initialization flow is not guaranteed to be unique and is not generally suitable for disambiguation purposes.
+
 ## Security considerations
 
 When exposing tools:

docs/specification/2025-06-18/basic/transports.mdx

@@ -253,7 +253,7 @@ initialization](/specification/2025-06-18/basic/lifecycle#version-negotiation).
 For backwards compatibility, if the server does _not_ receive an `MCP-Protocol-Version`
 header, and has no other way to identify the version - for example, by relying on the
 protocol version negotiated during initialization - the server **SHOULD** assume protocol
-version `2025-06-18`.
+version `2025-03-26`.
 
 If the server receives a request with an invalid or unsupported
 `MCP-Protocol-Version`, it **MUST** respond with `400 Bad Request`.

docs/specification/draft/basic/transports.mdx

@@ -253,7 +253,7 @@ initialization](/specification/draft/basic/lifecycle#version-negotiation).
 For backwards compatibility, if the server does _not_ receive an `MCP-Protocol-Version`
 header, and has no other way to identify the version - for example, by relying on the
 protocol version negotiated during initialization - the server **SHOULD** assume protocol
-version `2025-06-18`.
+version `2025-03-26`.
 
 If the server receives a request with an invalid or unsupported
 `MCP-Protocol-Version`, it **MUST** respond with `400 Bad Request`.