[azsdk-cli] add tsp list_topics and tsp get_topic_docs tools (mcp only)

[chrisradek]

Resolves #11679

This PR adds 2 new MCP tools whose purpose is to allow retrieving TypeSpec and TypeSpec Azure documentation.

azsdk_list_typespec_topics

This tool returns a list of "topics" that the agent can request documentation for (e.g. typespec-language-basics, typespec-azure-clients-how-tos) along with their descriptions.

Currently, the TypeSpec/TypeSpec Azure doc websites have been updated to generate these topics whenever they are built:

• TypeSpec llms.json
• TypeSpec Azure llms.json

azsdk_get_typespec_topics_docs

This tool takes in a list of "topics" (must be a topic returned by list_typespec_topics), and returns the documentation for those topics.

The documentation is hosted on the TypeSpec/TypeSpec Azure doc websites in llms-full.txt format - big markdown files.

Why 2 tools?

Trying to fit all the content currently spread across multiple llms-full.txt files would take hundreds of thousands of tokens - overwhelming a lot of context windows today. In my earlier testing, I found that it was also helpful to give targeted documentation. For example, only giving the azure core docs when working on a data plane service, instead of the ARM docs too.

[Copilot]

Pull Request Overview

This PR adds two new MCP tools to enable retrieving TypeSpec and TypeSpec Azure documentation. The tools provide a way to list available documentation topics and fetch their content, allowing for targeted documentation retrieval instead of overwhelming context windows with all available content.

• Adds azsdk_list_typespec_topics tool to list available documentation topics with descriptions
• Adds azsdk_get_typespec_topics_docs tool to fetch documentation content for specified topics
• Implements a TypeSpecDocsService with caching and thread-safe operations

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
TspInitTool.cs	Adds two new MCP tools with dependency injection for TypeSpecDocsService
TypeSpecDocsService.cs	Core service implementing documentation fetching with caching and concurrency management
ServiceRegistrations.cs	Registers HTTP client and TypeSpecDocsService in DI container
TypeSpecTopicDoc.cs	Model for topic documentation content
TypeSpecTopic.cs	Model for topic metadata
ListTypeSpecTopicsResponse.cs	Response model for listing topics
GetTypeSpecTopicsDocsResponse.cs	Response model for topic documentation
LlmsJsonItem.cs	Model for parsing llms.json files
TspInitToolTest.cs	Updates test constructor calls to include new service dependency
TypeSpecDocsServiceTests.cs	Comprehensive test suite for the new service

[Copilot]

The lambda function parameter name urlKey shadows the outer variable url. This could lead to confusion and potential bugs. Use the outer url parameter directly or choose a different parameter name.

Suggested change

	var task = inflightRequests.GetOrAdd(url, async (urlKey) =>
	{
	try
	{
	using var httpClient = httpClientFactory.CreateClient();
	var response = await httpClient.GetStringAsync(urlKey, ct);
	return response;
	}
	finally
	{
	// Remove from in-flight when done
	inflightRequests.TryRemove(urlKey, out _);
	var task = inflightRequests.GetOrAdd(url, async (dedupUrl) =>
	{
	try
	{
	using var httpClient = httpClientFactory.CreateClient();
	var response = await httpClient.GetStringAsync(dedupUrl, ct);
	return response;
	}
	finally
	{
	// Remove from in-flight when done
	inflightRequests.TryRemove(dedupUrl, out _);

[Copilot]

[nitpick] The comment indicates a workaround for a DI issue. Consider using a more explicit approach like checking sources.Any() or implementing a proper factory pattern to handle this dependency injection concern more clearly.

[Copilot]

[nitpick] Use .Any() instead of .Count != 0 for better readability and potential performance benefits when checking if a collection has elements.

[praveenkuttappan]

When should this be called by LLM? Can you please share sample prompt from user that will invoke this tool?

[praveenkuttappan]

I feel that this description needs a bit more explanation to make it easier for LLM to decide.

[praveenkuttappan]

nit: empty line