Python: added inline yaml sample

[eavanvalkenburg]

Motivation and Context

Added a sample using a inline yaml definition to simplify explaining this, and made a fix in one other sample.
Also added description fields to Foundry clients and Assistants clients and updated _update_name method to update_name_and_description to propagate from Agent to ChatClient, when ChatClient values are not set.

Closes: #2570

Description

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[Copilot]

Pull request overview

This PR adds a new Python sample demonstrating how to create an agent using an inline YAML definition string, making it easier to understand declarative agent creation without needing external YAML files. It also fixes a parameter naming issue in an existing sample.

• Added a new inline_yaml.py sample showing inline YAML agent definition
• Fixed the get_weather_agent.py sample by explicitly naming the chat_client parameter
• Updated documentation to include the new sample

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
python/samples/getting_started/declarative/inline_yaml.py	New sample demonstrating inline YAML agent creation with Azure AI Foundry credentials
python/samples/getting_started/declarative/get_weather_agent.py	Fixed parameter naming by explicitly using chat_client= keyword argument
python/samples/getting_started/declarative/README.md	Updated documentation to include the new inline YAML sample with description and usage instructions
python/uv.lock	Updated dependency lock file with newer versions of fastapi and modified platform markers
python/.vscode/settings.json	Added personal VS Code environment configuration settings

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/azure-ai/agent_framework_azure_ai
_chat_client.py	414	79	80%	296, 525–526, 528, 531, 534–539, 541, 549, 561–563, 567, 570–571, 579–582, 592, 600–603, 605–606, 608–609, 616, 624–625, 633–634, 639–640, 644–651, 656–657, 665, 671, 679–681, 684, 706–707, 769, 784, 796–800, 827–829, 832–833, 891–896, 917, 958, 967, 993
_client.py	164	30	81%	174–177, 181–182, 184, 225, 227–230, 232, 369–372, 376, 378–379, 381–389, 391
packages/core/agent_framework
_agents.py	290	51	82%	329, 390–392, 438, 492, 510, 672, 853, 856–858, 986–989, 991, 994–996, 1084, 1125, 1127, 1136–1141, 1147, 1149, 1159–1160, 1167, 1169–1170, 1178–1182, 1190–1191, 1193, 1198, 1200, 1234, 1277–1278, 1280, 1293
observability.py	610	101	83%	238, 264–266, 268, 270–274, 282–283, 288–289, 294–299, 322–324, 326–327, 333, 417, 427, 449, 455, 474–476, 484–486, 509–511, 521–523, 656, 658, 745–749, 752–756, 765–768, 778–781, 783, 1050, 1128–1130, 1200–1202, 1360, 1368, 1372, 1376, 1382, 1384, 1386, 1394, 1404, 1432–1433, 1446–1449, 1468–1470, 1472–1475, 1477–1478, 1482, 1485, 1543, 1559, 1563, 1697, 1699
packages/core/agent_framework/azure
_assistants_client.py	35	0	100%
packages/core/agent_framework/openai
_assistants_client.py	209	29	86%	179, 192, 195, 201–202, 205, 208, 211–212, 223, 248, 250, 252, 254, 256, 259, 262, 265, 269, 280, 365, 402, 438, 467–470, 521, 538
TOTAL	15895	2419	84%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
2282	130 💤	0 ❌	0 🔥	58.566s ⏱️