docs(agents): md-Werkzeug für lange Markdown-Dateien in Tooling aufgenommen

Outline mit Token-Größe pro Abschnitt, dann gezielt den Teilbaum lesen —
statt head oder grep auf Überschriftenzeilen.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014Jmx1FL5pssYBKsCjj2pJr

agents/AGENTS.md

@@ -110,8 +110,12 @@ credentials or customer-personal data.
   was a problem with X" costs more time than it saves.
 - No need to economize on characters: cognee has no size limit, so write
   notes comprehensively and self-contained.
-- Always keep the external references and source links (Confluence, Jira,
-  TeamVault, ...) in the note — they matter.
+- Always keep the external references and source links in the note — they
+  matter: Confluence, Jira, TeamVault, and, for notes that grew out of a Google
+  Chat discussion, the source-thread URLs
+  (`https://chat.google.com/room/<SPACE-ID>/<THREAD-ID>`, for individual
+  messages append the `<MESSAGE-ID>`) so the original discussion stays
+  traceable — not just a separate index.
 
 ## Sandbox
 
@@ -158,12 +162,30 @@ credentials or customer-personal data.
   [`ccc`](https://github.com/cocoindex-io/cocoindex-code). Reach for
   it on conceptual questions ("where is X used / which files do Y /
   what handles Z"), where a keyword grep would miss indirect usage:
-  `ccc search '<concept>' --path '**'`. Pass `--path '**'` — without
-  it, results are filtered to the current working directory's
-  subtree. The `ccc` skill has the full reference;
-  `grep`/`rg`/`find` remain fine for exact-string lookups.
+  `ccc search '<concept>'`. Results are filtered to the current working
+  directory's subtree, so **run the search from the project root** — that is
+  the cheap way to see everything. `--path '**'` achieves the same from a
+  subdirectory, but from the root it is a no-op *and* about three times
+  slower (measured 2026-09-02 on a 1005-file index: 0.35 s against 0.12 s,
+  identical hits), so pass it only when you cannot control the cwd.
+  **Embeddings only, no keyword component:** searching an exact string
+  (a UUID, a ticket ID, an error message) does not return the file that
+  contains it — verified. `grep`/`rg`/`find` own exact-string lookups.
+  A low score is a warning, not a hit. The `ccc` skill has the full
+  reference.
 - **`ccc index` / `ccc init` are read-safe maintenance.** They only
   write to the gitignored `.cocoindex_code/` directory, never to
   source. Run them without confirmation prompts — at session start,
   after refactors, or before a search when the index may be stale.
   Treat like `grep` for permission purposes, not like a code edit.
+- **`md` für lange Markdown-Dateien statt `head`/`grep -n '^#'`.**
+  Global auf dem PATH (`~/.local/bin/md` → `~/Projekte/ai/bin/md`).
+  `md outline <datei>` gibt den Überschriftenbaum mit Zeilennummer und
+  Größe pro Abschnitt (`[164 Zeilen, ~2.1k Tok]`) — daraus die
+  Lese-Entscheidung treffen, dann `md section <datei> "<Überschrift>"`
+  für genau diesen Teilbaum (Query auch als Slug oder `L48`; `--range`
+  liefert `offset limit` fürs Read-Tool, `--depth 0` schneidet
+  Unterabschnitte ab). Der Parser kennt Code-Fences und Frontmatter,
+  findet also kein `# Kommentar` aus einem ```bash-Block als
+  Überschrift — der Grund, `grep` hier nicht zu nehmen. Bei Dateien
+  unter ~500 Zeilen direkt `Read`, der Umweg lohnt erst darüber.