[DaleSeo]

Motivation and Context

SEP-2640 serves Agent Skills through the Resources primitive, so an MCP server can ship workflow instructions alongside its tools. This PR adds the Skills extension, io.modelcontextprotocol/skills, with skills/list, skills/get, and the optional resources/directory/read methods on both the server and client sides. It only adds the protocol surface. A filesystem catalog will come in a second PR.

How Has This Been Tested?

Added tests

Breaking Changes

None

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

[github-actions]

@DaleSeo (assignment failed) is on triage rotation this week and is the reviewer for this one.

Labels come from the PR labeler. Please review the change.

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