docs(schema): require session/resume cwd to match the session (#2612)

* docs(schema): require session/resume cwd to match the session

* docs(schema): make the resume cwd match a SHOULD

Author: benbrandt

agent-client-protocol-schema/src/v2/agent.rs

@@ -1241,6 +1241,9 @@ pub struct ResumeSessionRequest {
     /// The ID of the session to resume.
     pub session_id: SessionId,
     /// The working directory for this session. Must be an absolute path.
+    ///
+    /// Clients SHOULD send the session's working directory. Agents that can't resume a session
+    /// in a different directory reject it with `-32602`, and MAY normalize paths when comparing.
     pub cwd: AbsolutePath,
     /// Additional workspace roots to activate for this session. Each path must be absolute.
     ///

docs/protocol/v2/draft/schema.mdx

@@ -1017,6 +1017,10 @@ the request `cwd` matches the session's `cwd`.
 </ResponseField>
 <ResponseField name="cwd" type={<a href="#absolutepath">AbsolutePath</a>} required>
   The working directory for this session. Must be an absolute path.
+
+Clients SHOULD send the session's working directory. Agents that can't resume a session
+in a different directory reject it with `-32602`, and MAY normalize paths when comparing.
+
 </ResponseField>
 <ResponseField name="mcpServers" type={<a href="#mcpserver">McpServer[]</a>} >
   List of MCP servers to connect to for this session.

docs/protocol/v2/draft/session-setup.mdx

@@ -524,6 +524,8 @@ The `cwd` (current working directory) parameter establishes the primary file sys
 - **MUST** remain the base for relative-path resolution
 - **MUST** be part of the session's effective root set
 
+On `session/resume`, Clients **SHOULD** send the session's working directory. Agents that can't resume a session in a different directory reject it with `-32602`. Agents **MAY** normalize paths when comparing, for example ignoring a trailing separator.
+
 When `session.additionalDirectories` is in use, the session's effective root set is `[cwd, ...additionalDirectories]`. This root set **SHOULD** serve as a boundary for tool operations on the file system.
 
 ### Workspace Root Security

docs/protocol/v2/schema.mdx

@@ -675,6 +675,10 @@ the request `cwd` matches the session's `cwd`.
 </ResponseField>
 <ResponseField name="cwd" type={<a href="#absolutepath">AbsolutePath</a>} required>
   The working directory for this session. Must be an absolute path.
+
+Clients SHOULD send the session's working directory. Agents that can't resume a session
+in a different directory reject it with `-32602`, and MAY normalize paths when comparing.
+
 </ResponseField>
 <ResponseField name="mcpServers" type={<a href="#mcpserver">McpServer[]</a>} >
   List of MCP servers to connect to for this session.

docs/protocol/v2/session-setup.mdx

@@ -455,6 +455,8 @@ The `cwd` (current working directory) parameter establishes the primary file sys
 - **MUST** remain the base for relative-path resolution
 - **MUST** be part of the session's effective root set
 
+On `session/resume`, Clients **SHOULD** send the session's working directory. Agents that can't resume a session in a different directory reject it with `-32602`. Agents **MAY** normalize paths when comparing, for example ignoring a trailing separator.
+
 When `session.additionalDirectories` is in use, the session's effective root set is `[cwd, ...additionalDirectories]`. This root set **SHOULD** serve as a boundary for tool operations on the file system.
 
 ### Workspace Root Security

schema/v2/schema.json

@@ -6859,7 +6859,7 @@
           ]
         },
         "cwd": {
-          "description": "The working directory for this session. Must be an absolute path.",
+          "description": "The working directory for this session. Must be an absolute path.\n\nClients SHOULD send the session's working directory. Agents that can't resume a session\nin a different directory reject it with `-32602`, and MAY normalize paths when comparing.",
           "allOf": [
             {
               "$ref": "#/$defs/AbsolutePath"

schema/v2/schema.unstable.json

@@ -8165,7 +8165,7 @@
           ]
         },
         "cwd": {
-          "description": "The working directory for this session. Must be an absolute path.",
+          "description": "The working directory for this session. Must be an absolute path.\n\nClients SHOULD send the session's working directory. Agents that can't resume a session\nin a different directory reject it with `-32602`, and MAY normalize paths when comparing.",
           "allOf": [
             {
               "$ref": "#/$defs/AbsolutePath"