diff --git a/src/personal_mcp/registry/models/registry.py b/src/personal_mcp/registry/models/registry.py
index a9b1659..bc5257d 100644
--- a/src/personal_mcp/registry/models/registry.py
+++ b/src/personal_mcp/registry/models/registry.py
@@ -199,16 +199,27 @@ class DocsRegistry(StrictFrozenModel):
     """In-memory index of loaded skills, prompts, and docs content."""
 
     skills_by_id: Mapping[str, SkillRecord] = Field(default_factory=frozen_mapping)
+    """Maps each skill identifier to its fully resolved registry record."""
     skills_in_load_order: tuple[str, ...]
+    """Preserves skill identifiers in deterministic source loading order."""
     skills_summary_in_load_order: tuple[SkillSummaryRecord, ...]
+    """Stores compact skill summaries in the same deterministic loading order."""
     docs_markdown_by_path: Mapping[DocsPath, str] = Field(default_factory=_empty_docs_mapping)
+    """Maps each documentation path to its loaded Markdown content."""
     docs_markdown_path_index: tuple[DocsPath, ...]
+    """Lists documentation paths in deterministic index order."""
     tag_to_skill_ids: Mapping[str, tuple[str, ...]] = Field(default_factory=frozen_mapping)
+    """Indexes skill identifiers by tag for catalog filtering and search."""
     capability_to_skill_ids: Mapping[str, tuple[str, ...]] = Field(default_factory=frozen_mapping)
+    """Indexes skill identifiers by the capabilities they provide."""
     prompts_by_id: Mapping[str, PromptRecord] = Field(default_factory=frozen_mapping)
+    """Maps each prompt identifier to its fully resolved registry record."""
     prompts_in_load_order: tuple[str, ...] = ()
+    """Preserves prompt identifiers in deterministic source loading order."""
     prompts_summary_in_load_order: tuple[PromptSummaryRecord, ...] = ()
+    """Stores compact prompt summaries in the same deterministic loading order."""
     tag_to_prompt_ids: Mapping[str, tuple[str, ...]] = Field(default_factory=frozen_mapping)
+    """Indexes prompt identifiers by tag for catalog filtering and search."""
 
     @field_validator(
         "skills_by_id",