docs: Add Rustdoc comments for various structs and functions

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/modes/server/mcp/mod.rs

@@ -3,6 +3,10 @@ pub mod tools;
 
 pub use server::KeepMcpServer;
 
+/// Module for handling MCP (Model Context Protocol) requests in the server.
+///
+/// Provides handlers for JSON-RPC style requests to interact with Keep's storage
+/// via the API.
 use axum::{
     extract::State,
     http::StatusCode,
@@ -15,46 +19,69 @@ use serde_json::Value;
 use crate::modes::server::common::AppState;
 use crate::modes::server::common::ApiResponse;
 
+/// Request structure for MCP JSON-RPC calls.
+///
+/// # Fields
+///
+/// * `method` - The MCP method name (e.g., "save_item").
+/// * `params` - Optional JSON parameters for the method.
 #[derive(Deserialize)]
 pub struct McpRequest {
     pub method: String,
     pub params: Option<Value>,
 }
 
-pub async fn handle_mcp_request(
-    State(state): State<AppState>,
-    Json(request): Json<McpRequest>,
-) -> impl IntoResponse {
-    let mcp_server = KeepMcpServer::new(state);
-    
-    match mcp_server.handle_request(&request.method, request.params).await {
-        Ok(result) => {
-            match serde_json::from_str(&result) {
-                Ok(parsed_result) => {
-                    let response = ApiResponse {
-                        success: true,
-                        data: Some(parsed_result),
-                        error: None,
-                    };
-                    (StatusCode::OK, Json(response))
-                }
-                Err(_) => {
-                    let response = ApiResponse {
-                        success: true,
-                        data: Some(serde_json::Value::String(result)),
-                        error: None,
-                    };
-                    (StatusCode::OK, Json(response))
+    /// Handles an MCP request via the Axum framework.
+    ///
+    /// Parses the JSON request, delegates to `KeepMcpServer`, and returns an API response.
+    /// Attempts to parse the result as JSON; falls back to string if invalid.
+    ///
+    /// # Arguments
+    ///
+    /// * `State(state)` - The application state.
+    /// * `Json(request)` - The deserialized MCP request.
+    ///
+    /// # Returns
+    ///
+    /// An `IntoResponse` with status code and JSON API response.
+    ///
+    /// # Errors
+    ///
+    /// Returns 400 Bad Request on handler errors.
+    pub async fn handle_mcp_request(
+        State(state): State<AppState>,
+        Json(request): Json<McpRequest>,
+    ) -> impl IntoResponse {
+        let mcp_server = KeepMcpServer::new(state);
+        
+        match mcp_server.handle_request(&request.method, request.params).await {
+            Ok(result) => {
+                match serde_json::from_str(&result) {
+                    Ok(parsed_result) => {
+                        let response = ApiResponse {
+                            success: true,
+                            data: Some(parsed_result),
+                            error: None,
+                        };
+                        (StatusCode::OK, Json(response))
+                    }
+                    Err(_) => {
+                        let response = ApiResponse {
+                            success: true,
+                            data: Some(serde_json::Value::String(result)),
+                            error: None,
+                        };
+                        (StatusCode::OK, Json(response))
+                    }
                 }
             }
-        }
-        Err(e) => {
-            let response = ApiResponse {
-                success: false,
-                data: None,
-                error: Some(e.to_string()),
-            };
-            (StatusCode::BAD_REQUEST, Json(response))
+            Err(e) => {
+                let response = ApiResponse {
+                    success: false,
+                    data: None,
+                    error: Some(e.to_string()),
+                };
+                (StatusCode::BAD_REQUEST, Json(response))
+            }
         }
     }
-}