Overhaul tool handling

[stephentoub]

• Renames [McpTool{Type}] to [McpServerTool{Type}], in order to distinguish representations of tools on the server from tools on the client.
• Enables [McpServerTool] methods to have arguments injected from DI, as well as a specific set of types from the implementation directly, like IMcpServer.
• Renames WithTools to WithToolsFromAssembly.
• All of the WithToolsXx methods now publish each individual McpServerTool into DI; other code can do so as well. The options setup code gathers all of the tools from DI and combines them into a collection which is then stored in McpServerOptions and used to construct the server.
• The server tools specified via DI as well as manually-provided handlers, using CallToolHandler as a fallback in case the requested tool doesn't exist in the tools collection, and ListToolsHandler augments the information for whatever tools exist.
• The tools are stored in McpServerOptions in a new McpServerToolCollection type, which is a thread-safe container that exposes add/removal notification. Adding/removing tools triggers a change notification that in turn sends a notification to the client about a tools update.
• The ServerOptions are exposed from the server instance.
• Removed cursor-based APIs from McpClientExtensions.
• Changed McpClientExtensions APIs to return Task<IList<...> rather than IAsyncEnumerable<...>.

I'm sure this will need to evolve further before we're "done", but it's a significant improvement from where we are now. One area I'm not super happy with is the notifying collection; that might work ok for a stdio server, where you can grab the created collection from the server's options and mutate it, but I don't know how well that's going to work for sse servers.

Closes #26
Closes #27
Closes to #62
Contributes to #67
Closes #68
Contributes to #69
Closes #79
Contributes to #41

[stephentoub]

@colombod, please take a look. I'm not sure if this will fully meet your needs, but it's in the right direction, so my request would be after this merges, please experiment, and come back with a draft PR to address any gaps.

[stephentoub]

@aaronpowell, please take a look, based on your feedback about supporting both a tool collection and tool handlers as fallbacks.

[Copilot]

Pull Request Overview

This PR overhauls the tool handling functionality by renaming tool-related types and improving dependency injection support. Key changes include renaming McpTool types to McpServerTool types, updating DI registrations with WithToolsFromAssembly, and revising client APIs to return IList rather than IAsyncEnumerable.

Reviewed Changes

Copilot reviewed 42 out of 44 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/ModelContextProtocol/AIContentExtensions.cs	Adds AI content conversion helpers with new collection initialization syntax changes
src/ModelContextProtocol/Client/McpClientTool.cs	Introduces a new client-side tool function wrapper
samples/AspNetCoreSseServer/Tools/SampleLlmTool.cs	Updates tool attributes and method signatures to use server-oriented DI injections
src/ModelContextProtocol/Configuration/McpServerOptionsSetup.cs	Adjusts options setup to integrate the new tool collection from DI
src/ModelContextProtocol/Client/McpClientExtensions.cs	Revises listing and invoking of tools/prompts/resources with updated return types
src/ModelContextProtocol/Configuration/McpServerBuilderExtensions.Tools.cs	Refactors tool extension methods to use the new attribute and registration approach
README.MD	Updates documentation snippets to reflect the renaming and new API usage
Other sample files	Updates tool attribute names and DI registration calls

Files not reviewed (2)

• Directory.Packages.props: Language not supported
• samples/ChatWithTools/ChatWithTools.csproj: Language not supported

Comments suppressed due to low confidence (2)

src/ModelContextProtocol/AIContentExtensions.cs:22

• The array initializer using square brackets is not standard C# syntax. Consider using a collection initializer like 'new List { ToAIContent(promptMessage.Content) }'.

Contents = [ToAIContent(promptMessage.Content)]

src/ModelContextProtocol/Client/McpClientExtensions.cs:90

• Initializing the collection 'prompts' as null can lead to null returns; consider initializing it with an empty list (e.g. 'new List()') to simplify accumulation and avoid potential null issues.

List<Prompt>? prompts = null;

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[stephentoub]

@halter73, please take a look, in particular at the DI-related stuff, plus all of the lovely code required to deal with records in the options types, per our conversation earlier today.

[aaronpowell]

Overall it looks like it should tackle the issue. I'll combine it with my branch for the Everything Server and have a test.

[halter73]

I like the renames to WithToolsFromAssembly and McpServerToolType.