Add "Choose the right .NET AI tool" guidance article

[Copilot]

The .NET AI ecosystem has grown to include a dozen distinct components (MEAI, MAF, MEDI, MEVD, MCP Server/Client, Evaluations, AI Toolkit, Copilot SDK, Azure AI Foundry, Foundry Local, Aspire) with no clear guidance on when to reach for each one. This adds a dedicated conceptual article derived from the netaiguidance positioning work.

New article: docs/ai/conceptual/choose-ai-tool.md

• Quick-reference table — all 12 components with "use it when" / "don't lead with it when" columns for fast scanning
• Decision tree section — maps primary challenge (add AI behavior, work with own data, share/consume capabilities, agentic system, hosting model, dev workflow) to the right component(s)
• Per-component sections — "use when," "don't use when," important architectural boundaries, and cross-links to deeper docs
• Common combinations — canonical stacks (RAG, multi-agent, enterprise cloud, local-first)

Existing doc updates

• dotnet-ai-ecosystem.md — TIP callout at the top directing readers to the new article when unsure which tool to use
• overview.md — sentence added in learning path section pointing to the new article
• toc.yml — new article added under Concepts

---

Internal previews

📄 File	🔗 Preview link
docs/ai/conceptual/calling-tools.md	AI tool calling
docs/ai/conceptual/data-ingestion.md	Data ingestion
docs/ai/conceptual/medi-library.md	The Microsoft.Extensions.DataIngestion library
docs/ai/conceptual/mevd-library.md	docs/ai/conceptual/mevd-library
docs/ai/dotnet-ai-ecosystem.md	.NET + AI ecosystem tools and SDKs
docs/ai/evaluation/libraries.md	The Microsoft.Extensions.AI.Evaluation libraries
docs/ai/get-started-mcp.md	Get started with .NET AI and MCP
docs/ai/overview.md	Develop .NET apps with AI features
docs/ai/toc.yml	docs/ai/toc
docs/ai/vector-stores/overview.md	Vector databases for .NET AI apps

[gewarren]

@copilot A few requests:

• Add the new article to the index.yml file
• Use xref links to namespaces in the new article
• Add links to AI Toolkit docs or extension
• The name for Aspire is just "Aspire", not ".NET Aspire"

[Copilot]

@copilot A few requests:

• Add the new article to the index.yml file
  ...

Done in commit e8f7ddc:

• Added the article to index.yml in the Essential concepts card.
• Replaced backtick namespace names with xref links: <xref:Microsoft.Extensions.AI>, <xref:Microsoft.Extensions.AI.Evaluations>, <xref:Microsoft.Extensions.DataIngestion>, and <xref:Microsoft.Extensions.VectorData>.
• Added a "For more information" link to AI Toolkit for Visual Studio Code at the end of the AI Toolkit section.
• Changed ".NET Aspire" to "Aspire" throughout the article.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• code.visualstudio.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• marketplace.visualstudio.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[gewarren]

@copilot Also add links to more info on Copilot SDK and Foundry Tools.

[gewarren]

@copilot Also add links to more info on Copilot SDK and Foundry Tools. And turn the bullets on line 36 into a table.

[Copilot]

@copilot Also add links to more info on Copilot SDK and Foundry Tools.

Done in commit c3ae6f2 — added "For more information" links to the Copilot SDK repository and the Foundry Local documentation.

@copilot Also add links to more info on Copilot SDK and Foundry Tools. And turn the bullets on line 36 into a table.

Done in commit c3ae6f2 — converted the "How to decide" bullets to a decision table, and added "For more information" links to the Copilot SDK and Foundry Local docs.

[Copilot]

Pull request overview

This PR updates the .NET AI documentation set to improve discoverability and guidance across the ecosystem by adding new conceptual library pages, refining existing conceptual overviews, and reshaping the navigation structure.

Changes:

• Add new conceptual articles for AI tool calling, Microsoft.Extensions.DataIngestion, and Microsoft.Extensions.VectorData.
• Refresh the “.NET + AI ecosystem tools and SDKs” overview with a “Decide which tool to use” section and updated component descriptions.
• Update TOC entries and redirects to reflect renamed/reorganized conceptual content (including tool-calling).

Reviewed changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
docs/ai/vector-stores/overview.md	Simplifies the MEVD section and points readers to the new MEVD conceptual article.
docs/ai/toc.yml	Adds new top-level entries (evaluation, ingestion, vector data, MCP) and updates tool-calling navigation.
docs/ai/overview.md	Adds a pointer to the “Decide which tool to use” guidance section.
docs/ai/get-started-mcp.md	Expands “See also” with links to MCP client/server quickstarts and labels blog links.
docs/ai/evaluation/libraries.md	Adds a quickstart cross-link in “See also”.
docs/ai/dotnet-ai-ecosystem.md	Adds a “Decide which tool to use” section and rewrites component guidance sections.
docs/ai/conceptual/mevd-library.md	New conceptual overview for Microsoft.Extensions.VectorData.
docs/ai/conceptual/medi-library.md	New conceptual overview for Microsoft.Extensions.DataIngestion.
docs/ai/conceptual/data-ingestion.md	Removes duplicated library overview content and links to the new MEDI library page.
docs/ai/conceptual/calling-tools.md	New conceptual overview for tool/function calling with MEAI.
.openpublishing.redirection.ai.json	Adds a redirect from the old tool-calling page to the new calling-tools page.

Comments suppressed due to low confidence (1)

docs/ai/toc.yml:29

• The TOC now contains two adjacent entries that both route to get-started-mcp.md ("MCP client/server overview" and "C# SDK for MCP"). That duplication makes navigation ambiguous. Either remove one entry, or point "C# SDK for MCP" to a distinct page (for example, a dedicated SDK overview) so each TOC node has a unique purpose.

  - name: MCP client/server overview
    href: get-started-mcp.md
  - name: Microsoft Agent Framework
    href: /agent-framework/overview/agent-framework-overview?toc=/dotnet/ai/toc.json&bc=/dotnet/ai/toc.json
  - name: C# SDK for MCP
    href: get-started-mcp.md