Python: [BREAKING] Support code-defined agent skills

[SergeyMenshykh]

Summary

Adds support for code-defined agent skills — skills defined entirely in Python code using AgentSkill and AgentSkillResource classes, complementing the existing file-based SKILL.md approach.

Changes

Core (packages/core/agent_framework/_skills/)

• Refactored single _skills.py module into a _skills/ package:
  • _models.py — AgentSkill and AgentSkillResource data model classes
  • _agent_skills_provider.py — AgentSkillsProvider (renamed from FileAgentSkillsProvider) supporting both file-based and code-defined skills
  • __init__.py — public API exports
• AgentSkillsProvider now accepts a skills parameter for code-defined AgentSkill instances
• AgentSkill.resource decorator for attaching dynamic callable resources
• Removed backtick-quoted text matching for resource references; file-based resources are now discovered by scanning the skill directory for files with matching extensions

Samples

• Added code_skill sample demonstrating two patterns:
  1. Basic code skill with static resources
  2. Dynamic resources via @skill.resource decorator
• Fixed basic_skill/README.md incorrect directory/file names
• Fixed basic_skill/basic_skill.py Example 2 to be genuinely multi-turn

Tests

• Comprehensive test coverage for code-defined skills, combined file+code scenarios, XML formatting, validation, and resource reading

Related Issues

• Closes Python: FileAgentSkillsProvider incorrectly treats backtick-quoted text in SKILL.md as resource references #4369
• Related to Python: Support programmatic skills #4347

[Mark Wallace (markwallace-microsoft)]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/core/agent_framework
_skills.py	285	8	97%	563, 602–603, 676, 681, 833–834, 1044
TOTAL	22313	2754	87%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
4836	247 💤	0 ❌	0 🔥	1m 16s ⏱️

[Copilot]

Pull request overview

Adds Python support for code-defined agent skills, enabling skills to be declared in code (with optional dynamic resources) alongside existing file-based SKILL.md discovery.

Changes:

• Refactors skills support into agent_framework._skills package with new AgentSkill, AgentSkillResource, and AgentSkillsProvider.
• Extends the skills provider to register code-defined skills and expose dynamic resources via @skill.resource.
• Updates samples and expands core test coverage to include code-defined skills and combined scenarios.

Reviewed changes

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

Show a summary per file

File	Description
python/packages/core/agent_framework/_skills/_agent_skills_provider.py	New unified provider for file-based + code-defined skills, discovery helpers, prompt/tool wiring.
python/packages/core/agent_framework/_skills/_models.py	Introduces AgentSkill / AgentSkillResource models and @skill.resource decorator support.
python/packages/core/agent_framework/_skills/init.py	Exposes the new public skills API from the package.
python/packages/core/agent_framework/init.py	Updates public exports to the new skills API and removes the old provider export.
python/packages/core/tests/core/test_skills.py	Expands tests to cover code-defined skills, combined scenarios, formatting, discovery, and validation.
python/samples/02-agents/skills/basic_skill/basic_skill.py	Updates sample to use AgentSkillsProvider instead of the old provider.
python/samples/02-agents/skills/basic_skill/README.md	Fixes sample structure/run command and updates provider naming.
python/samples/02-agents/skills/code_skill/code_skill.py	Adds new sample demonstrating code-defined skills and dynamic resources.
python/samples/02-agents/skills/code_skill/README.md	Documents the new code-defined skills sample.
python/packages/core/agent_framework/_skills.py	Removes the legacy monolithic skills module in favor of the package layout.