Add experimental AI Evaluations topic page

sites/docs/src/content/ai/evals.md

@@ -0,0 +1,30 @@
+---
+title: AI Evaluations
+sidenav: ai
+description: >
+  Learn about Dart and Flutter's evaluation frameworks for measuring AI tooling
+  reliability.
+---
+
+:::experimental
+Evaluation tooling and benchmarks are experimental and likely to change.
+:::
+
+To explore the evaluation strategy,
+view the open-source dataset and scoring rubrics,
+or get involved with community benchmark datasets,
+visit the [Flutter Evals repository](https://github.com/flutter/evals).
+
+Evaluating the capabilities and reliability of AI agents requires testing
+approaches that model actual developer tasks.
+Because LLMs are non-deterministic,
+standard unit testing is insufficient for verifying agentic behaviors like
+codebase navigation, plan execution, and code synthesis.
+
+To build developer confidence in AI tooling,
+Dart and Flutter use an evaluation system ("evals")
+to test critical user journeys (CUJs).
+Evals measure both deterministic code correctness
+(compilation, lints, automated tests) and qualitative performance
+(reasoning, safety, and conciseness) using automated model judges
+and expert human grading.

sites/docs/src/data/sidenav/ai.yml

@@ -19,6 +19,8 @@
           permalink: /ai/gemini-cli-extension
     - title: Developer experience
       permalink: /ai/best-practices/developer-experience
+    - title: "AI Evaluations (experimental)"
+      permalink: /ai/evals
 
 - title: Build AI-powered apps
   expanded: true