Add missing exception documentation to public API surface

src/ModelContextProtocol.AspNetCore/McpEndpointRouteBuilderExtensions.cs

@@ -19,6 +19,7 @@ public static class McpEndpointRouteBuilderExtensions
     /// <param name="endpoints">The web application to attach MCP HTTP endpoints.</param>
     /// <param name="pattern">The route pattern prefix to map to.</param>
     /// <returns>Returns a builder for configuring additional endpoint conventions like authorization policies.</returns>
+    /// <exception cref="InvalidOperationException">The required MCP services have not been registered. Ensure <see cref="HttpMcpServerBuilderExtensions.WithHttpTransport"/> has been called during application startup.</exception>
     /// <remarks>
     /// For details about the Streamable HTTP transport, see the <see href="https://modelcontextprotocol.io/specification/2025-06-18/basic/transports#streamable-http">2025-06-18 protocol specification</see>.
     /// This method also maps legacy SSE endpoints for backward compatibility at the path "/sse" and "/message". For details about the HTTP with SSE transport, see the <see href="https://modelcontextprotocol.io/specification/2024-11-05/basic/transports#http-with-sse">2024-11-05 protocol specification</see>.

src/ModelContextProtocol.Core/Client/HttpClientTransportOptions.cs

@@ -10,6 +10,8 @@ public sealed class HttpClientTransportOptions
     /// <summary>
     /// Gets or sets the base address of the server for SSE connections.
     /// </summary>
+    /// <exception cref="ArgumentNullException">The value is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException">The value is not an absolute URI, or does not use the HTTP or HTTPS scheme.</exception>
     public required Uri Endpoint
     {
         get;

src/ModelContextProtocol.Core/Client/McpClientPrompt.cs

@@ -77,6 +77,7 @@ public McpClientPrompt(McpClient client, Prompt prompt)
     /// <param name="serializerOptions">The serialization options governing argument serialization.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ValueTask"/> containing the prompt's result with content and messages.</returns>
+    /// <exception cref="McpException">The request failed or the server returned an error response.</exception>
     /// <remarks>
     /// <para>
     /// This method sends a request to the MCP server to execute this prompt with the provided arguments.

src/ModelContextProtocol.Core/Client/McpClientResource.cs

@@ -76,6 +76,7 @@ public McpClientResource(McpClient client, Resource resource)
     /// </summary>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ValueTask{ReadResourceResult}"/> containing the resource's result with content and messages.</returns>
+    /// <exception cref="McpException">The request failed or the server returned an error response.</exception>
     /// <remarks>
     /// <para>
     /// This is a convenience method that internally calls <see cref="McpClient.ReadResourceAsync(string, RequestOptions, CancellationToken)"/>.

src/ModelContextProtocol.Core/Client/McpClientResourceTemplate.cs

@@ -80,6 +80,7 @@ public McpClientResourceTemplate(McpClient client, ResourceTemplate resourceTemp
     /// </param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ValueTask{ReadResourceResult}"/> containing the resource template's result with content and messages.</returns>
+    /// <exception cref="McpException">The request failed or the server returned an error response.</exception>
     public ValueTask<ReadResourceResult> ReadAsync(
         IReadOnlyDictionary<string, object?> arguments,
         CancellationToken cancellationToken = default) =>

src/ModelContextProtocol.Core/Client/StdioClientTransportOptions.cs

@@ -8,6 +8,7 @@ public sealed class StdioClientTransportOptions
     /// <summary>
     /// Gets or sets the command to execute to start the server process.
     /// </summary>
+    /// <exception cref="ArgumentException">The value is <see langword="null"/>, empty, or composed entirely of whitespace.</exception>
     public required string Command
     {
         get;

src/ModelContextProtocol.Core/McpSession.Methods.cs

@@ -18,6 +18,9 @@ public abstract partial class McpSession : IAsyncDisposable
     /// <param name="serializerOptions">The options governing request serialization.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A task that represents the asynchronous operation. The task result contains the deserialized result.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="method"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException"><paramref name="method"/> is empty or composed entirely of whitespace.</exception>
+    /// <exception cref="McpException">The request failed or the server returned an error response.</exception>
     public ValueTask<TResult> SendRequestAsync<TParameters, TResult>(
         string method,
         TParameters parameters,

src/ModelContextProtocol.Core/McpSession.cs

@@ -86,6 +86,8 @@ public abstract partial class McpSession : IAsyncDisposable
     /// <param name="method">The notification method.</param>
     /// <param name="handler">The handler to be invoked.</param>
     /// <returns>An <see cref="IDisposable"/> that will remove the registered handler when disposed.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="method"/> or <paramref name="handler"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException"><paramref name="method"/> is empty or composed entirely of whitespace.</exception>
     public abstract IAsyncDisposable RegisterNotificationHandler(string method, Func<JsonRpcNotification, CancellationToken, ValueTask> handler);
 
     /// <inheritdoc/>

src/ModelContextProtocol.Core/Protocol/ElicitRequestParams.cs

@@ -20,6 +20,7 @@ public sealed class ElicitRequestParams : RequestParams
     ///   <item><description><b>url</b>: Client navigates user to a URL for out-of-band interaction. Sensitive data is not exposed to the client.</description></item>
     /// </list>
     /// </remarks>
+    /// <exception cref="ArgumentException">The value is not "form" or "url".</exception>
     [JsonPropertyName("mode")]
     [field: MaybeNull]
     public string Mode

src/ModelContextProtocol.Core/Protocol/Tool.cs

@@ -39,6 +39,7 @@ public sealed class Tool : IBaseMetadata
     /// <summary>
     /// Gets or sets a JSON Schema object defining the expected parameters for the tool.
     /// </summary>
+    /// <exception cref="ArgumentException">The value is not a valid MCP tool JSON schema.</exception>
     /// <remarks>
     /// <para>
     /// The schema must be a valid JSON Schema object with the "type" property set to "object".
@@ -73,6 +74,7 @@ public JsonElement InputSchema
     /// <summary>
     /// Gets or sets a JSON Schema object defining the expected structured outputs for the tool.
     /// </summary>
+    /// <exception cref="ArgumentException">The value is not a valid MCP tool JSON schema.</exception>
     /// <remarks>
     /// <para>
     /// The schema must be a valid JSON Schema object with the "type" property set to "object".

src/ModelContextProtocol.Core/Server/McpServer.Methods.cs

@@ -52,6 +52,7 @@ public static McpServer Create(
     /// <returns>A task containing the sampling result from the client.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="requestParams"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">The client does not support sampling.</exception>
+    /// <exception cref="McpException">The request failed or the client returned an error response.</exception>
     public ValueTask<CreateMessageResult> SampleAsync(
         CreateMessageRequestParams requestParams,
         CancellationToken cancellationToken = default)
@@ -76,6 +77,7 @@ public ValueTask<CreateMessageResult> SampleAsync(
     /// <returns>A task containing the chat response from the model.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="messages"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">The client does not support sampling.</exception>
+    /// <exception cref="McpException">The request failed or the client returned an error response.</exception>
     public async Task<ChatResponse> SampleAsync(
         IEnumerable<ChatMessage> messages, ChatOptions? chatOptions = default, CancellationToken cancellationToken = default)
     {
@@ -222,6 +224,7 @@ public ILoggerProvider AsClientLoggerProvider() =>
     /// <returns>A task containing the list of roots exposed by the client.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="requestParams"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">The client does not support roots.</exception>
+    /// <exception cref="McpException">The request failed or the client returned an error response.</exception>
     public ValueTask<ListRootsResult> RequestRootsAsync(
         ListRootsRequestParams requestParams,
         CancellationToken cancellationToken = default)
@@ -245,6 +248,7 @@ public ValueTask<ListRootsResult> RequestRootsAsync(
     /// <returns>A task containing the elicitation result.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="requestParams"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">The client does not support elicitation.</exception>
+    /// <exception cref="McpException">The request failed or the client returned an error response.</exception>
     public ValueTask<ElicitResult> ElicitAsync(
         ElicitRequestParams requestParams, 
         CancellationToken cancellationToken = default)
@@ -272,6 +276,7 @@ public ValueTask<ElicitResult> ElicitAsync(
     /// <exception cref="ArgumentNullException"><paramref name="message"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException"><paramref name="message"/> is empty or composed entirely of whitespace.</exception>
     /// <exception cref="InvalidOperationException">The client does not support elicitation.</exception>
+    /// <exception cref="McpException">The request failed or the client returned an error response.</exception>
     /// <remarks>
     /// Elicitation uses a constrained subset of JSON Schema and only supports strings, numbers/integers, booleans and string enums.
     /// Unsupported member types are ignored when constructing the schema.