Add provenance docstrings to the new Skills tests

Author: Kludex

tests/client/extensions/test_skills.py

@@ -189,6 +189,7 @@ async def test_get_skill_returns_the_matching_entry() -> None:
 
 
 async def test_list_and_get_skill_preserve_skill_meta() -> None:
+    """ext-skills#157: a skill's optional `_meta` survives server -> wire -> client on both methods."""
     meta = {"example.com/owner": "platform"}
     skill_with_meta = Skill(
         uri=_SKILL_URI,

tests/server/test_skills.py

@@ -180,6 +180,8 @@ async def mutating_list(ctx: ServerRequestContext[Any, Any], params: ListSkillsP
 
 
 async def test_skills_list_sends_skill_meta_as_underscore_meta() -> None:
+    """ext-skills#157: a skill's optional metadata crosses the wire as `_meta`, not `meta`."""
+
     async def with_meta(ctx: ServerRequestContext[Any, Any], params: ListSkillsParams) -> ListSkillsResult:
         skill = _git_workflow_skill().model_copy(update={"meta": {"example.com/owner": "platform"}})
         return ListSkillsResult(skills=[skill])
@@ -344,6 +346,8 @@ async def test_directory_read_defaults_to_private_cache_scope_on_the_2026_07_28_
 
 
 async def test_directory_read_omits_cache_fields_on_a_legacy_wire() -> None:
+    """SEP-2549 fields are 2026-07-28+ only, and the runner's sieve skips extension methods,
+    so `Skills` strips them itself for an older connection."""
     async with Client(_server(with_directory_read=True), mode="legacy") as client:
         raw = await client.session.send_request(
             ReadDirectoryRequest(params=ReadDirectoryParams(uri="skill://git-workflow")), _RawResult