优化agent

backend/agent/skills/cad-engine/SKILL.md

@@ -13,15 +13,16 @@ Help an AI agent generate CAD models through the repository's CDSL engine.
 
 1. Use any injected CDSL part-skill bridge to establish the part structure,
    parameter roles, and feature order. It is planning guidance only.
-2. Submit a complete DesignIntent before reading CDSL references or generating
-   CDSL. It contains semantic structures and mappings, never sketch coordinates
-   or raw CAD code. The backend records canonical selected part skills.
+2. Record a concise natural-language design brief before reading CDSL references
+   or generating CDSL. The brief captures the intended structures, dependency
+   order, key dimensions, and explicit assumptions. It is reference context
+   only, never an executable CAD contract.
 3. Read the engine README, `profile_schema.json`, and `cdsl_schema.json`, then
    search the official CDSL library for schema-valid profiles and feature
    expressions. `cdsl_schema.json` is the executable input contract.
-4. Produce parameterized CDSL in feature dependency order, using the accepted
-   DesignIntent's feature IDs and mappings plus the part
-   plan for intent and CDSL references for concrete schema expressions.
+4. Produce parameterized CDSL in feature dependency order. CDSL is the sole
+   authoritative and executable model: choose its feature IDs, profiles,
+   selectors, and schema-valid expressions directly from the CDSL contract.
 5. Call the generation tool only when every chosen feature is executable by
    the current schema and runtime. Validate through the `cdsl_only` path,
    then generate STEP and GLB artifacts.
@@ -29,7 +30,8 @@ Help an AI agent generate CAD models through the repository's CDSL engine.
 ## Part-skill boundary
 
 - User requirements and the CDSL schema/runtime override bridge guidance;
-  CDSL examples are lower-priority expression references.
+  CDSL examples are lower-priority expression references. The textual design
+  brief is planning context and is never validated against the CDSL.
 - Do not expose upstream source skills directly or treat them as code. Use
   only the injected CDSL bridge content.
 - Never emit build123d source or invent an atomic, profile, selector, or