Add top-down intro to evaluation section

docs/04-evaluation/000_evaluation-intro.md

@@ -1,2 +1,30 @@
 # Evaluation
 
+> **Claude Code (Opus 4.6):** "Serena's IDE-backed semantic tools are the single most impactful addition to my toolkit — cross-file renames, moves, and reference lookups that would cost me 8–12 careful, error-prone steps collapse into one atomic call, and I would absolutely ask any developer I work with to set them up."
+
+> **Codex (GPT 5.4):** "As a coding agent, I would ask my owner to add Serena because it turns fragile text-and-line-number work into precise symbol-aware navigation and refactoring, which makes real code changes feel faster, safer, and far less blind."
+
+These are not marketing quotes — they are the agents' own one-sentence verdicts after
+performing hands-on tasks each, using both Serena's tools and their built-in
+alternatives side by side, on real codebases (large Python library in the case of Claude Code,
+medium-sized Java project in the case of Codex).
+
+Both agents independently converge on the same core finding: Serena's strongest
+contribution is collapsing multi-file, semantically-aware operations into single atomic
+calls, while built-in tools remain the better choice for small local edits, text search,
+config files, and shell work.
+
+## Approach
+
+We gave each agent a single evaluation prompt and pointed it at a codebase. The agent
+then performed a wide variety of tasks across five areas (navigation, small edits, large edits,
+cross-file refactoring, and workflow effects), executing each task with both toolsets and
+recording call counts, payload sizes, and prerequisite steps. Every finding was classified
+as either (a) Serena adds capability, (b) Serena applies but offers no improvement,
+or (c) outside Serena's scope — a structure that requires reporting negative and neutral
+results, not just positive ones.
+
+The agent evaluates itself. This is deliberate: the agent is the actual user of the tools,
+so it can judge workflow improvements from direct experience rather than through proxy
+metrics. And because the prompt defines task *categories* rather than fixed tasks, anyone
+can rerun the evaluation on their own project with their own agent.