diff --git a/EvoScientist/commands/implementation/experts.py b/EvoScientist/commands/implementation/experts.py
index 77e1e1d..9670f7f 100644
--- a/EvoScientist/commands/implementation/experts.py
+++ b/EvoScientist/commands/implementation/experts.py
@@ -199,12 +199,17 @@ class ExpertCommand(Command):
             )
             return
 
-        dispatchable = {s.name for s in _dispatchable_experts()}
-        if target not in dispatchable:
+        # Completion matches case-insensitively; honour the same here by
+        # resolving a case-variant to the on-disk name before membership.
+        by_lower = {s.name.lower(): s.name for s in _dispatchable_experts()}
+        canonical = by_lower.get(target.lower())
+        if canonical is None:
             from ...tools.skills_manager import list_expert_skills
 
-            installed = {s.name for s in list_expert_skills(include_system=True)}
-            if target not in installed:
+            installed = {
+                s.name.lower() for s in list_expert_skills(include_system=True)
+            }
+            if target.lower() not in installed:
                 ctx.ui.append_system(
                     f"No expert skill named '{target}'. `/experts` lists "
                     "installed ones.",
@@ -218,12 +223,12 @@ class ExpertCommand(Command):
                 )
             return
 
-        if target in runtime.active_teams:
-            runtime.active_teams = [n for n in runtime.active_teams if n != target]
-            ctx.ui.append_system(f"Dismissed expert: {target}", style="dim")
+        if canonical in runtime.active_teams:
+            runtime.active_teams = [n for n in runtime.active_teams if n != canonical]
+            ctx.ui.append_system(f"Dismissed expert: {canonical}", style="dim")
         else:
-            runtime.active_teams = [*runtime.active_teams, target]
-            ctx.ui.append_system(f"Invited expert: {target}", style="green")
+            runtime.active_teams = [*runtime.active_teams, canonical]
+            ctx.ui.append_system(f"Invited expert: {canonical}", style="green")
             # Case (c): expert was installed after agent construction, so it
             # will not reach ``task()`` until the graph is rebuilt. Cheap
             # always-print hint mirrors the /install-skill success message.
diff --git a/EvoScientist/commands/implementation/session.py b/EvoScientist/commands/implementation/session.py
index 62cc724..1cec25b 100644
--- a/EvoScientist/commands/implementation/session.py
+++ b/EvoScientist/commands/implementation/session.py
@@ -182,8 +182,21 @@ class ResumeCommand(Command):
         if restored_workspace:
             ctx.workspace_dir = restored_workspace
 
+        switched_thread = resolved != ctx.thread_id
         ctx.thread_id = resolved
 
+        # Invitations are session-scoped (see ChannelRuntime.active_teams);
+        # resuming a different thread is a session switch, so release them —
+        # uniform with /new. Resuming the current thread keeps them.
+        runtime = ctx.channel_runtime
+        if switched_thread and runtime is not None and runtime.active_teams:
+            dismissed = list(runtime.active_teams)
+            runtime.active_teams = []
+            ctx.ui.append_system(
+                f"Dismissed experts on session switch: {', '.join(dismissed)}",
+                style="dim",
+            )
+
         # Signal session change to UI
         if hasattr(ctx.ui, "handle_session_resume"):
             await ctx.ui.handle_session_resume(resolved, restored_workspace)
@@ -214,18 +227,19 @@ class NewCommand(Command):
     category = "Session"
 
     async def execute(self, ctx: CommandContext, args: list[str]) -> None:
-        # ``/new`` means fresh state — release any invited experts before
-        # starting the new session. Uniform with the ``ChannelRuntime.clear``
-        # path on channel shutdown; avoids the "why is idea-brainstorm still
-        # active in my new thread?" surprise. Users who want to reuse an
-        # invite in the next thread can re-invite explicitly.
+        # ``/new`` means fresh state — release any invited experts. Uniform
+        # with the ``ChannelRuntime.clear`` path on channel shutdown; avoids
+        # the "why is idea-brainstorm still active in my new thread?"
+        # surprise. Users who want to reuse an invite in the next thread can
+        # re-invite explicitly. Cleared only after the new session actually
+        # exists, so a failed start leaves the current session intact.
         runtime = ctx.channel_runtime
         dismissed: list[str] = []
         if runtime is not None and runtime.active_teams:
             dismissed = list(runtime.active_teams)
-            runtime.active_teams = []
         await ctx.ui.start_new_session()
         if dismissed:
+            runtime.active_teams = []
             ctx.ui.append_system(
                 f"Dismissed experts on new session: {', '.join(dismissed)}",
                 style="dim",
diff --git a/EvoScientist/stream/events.py b/EvoScientist/stream/events.py
index a8d5de6..9014170 100644
--- a/EvoScientist/stream/events.py
+++ b/EvoScientist/stream/events.py
@@ -293,12 +293,14 @@ class _V3EventProcessor:
                     description=description if isinstance(description, str) else "",
                 ).data
             ]
+        raw_duration = payload.get("duration_ms")
+        duration_ms = raw_duration if isinstance(raw_duration, int) else 0
         if phase == "complete":
             return [
                 self.emitter.panel_dispatch_complete(
                     eval_id=eval_id_str,
                     dispatch_id=dispatch_id,
-                    duration_ms=payload.get("duration_ms", 0),
+                    duration_ms=duration_ms,
                 ).data
             ]
         if phase == "error":
@@ -307,7 +309,7 @@ class _V3EventProcessor:
                 self.emitter.panel_dispatch_error(
                     eval_id=eval_id_str,
                     dispatch_id=dispatch_id,
-                    duration_ms=payload.get("duration_ms", 0),
+                    duration_ms=duration_ms,
                     error=error if isinstance(error, str) else "",
                 ).data
             ]
diff --git a/EvoScientist/subagents/expert_container_async.py b/EvoScientist/subagents/expert_container_async.py
index 97a669b..c397195 100644
--- a/EvoScientist/subagents/expert_container_async.py
+++ b/EvoScientist/subagents/expert_container_async.py
@@ -17,11 +17,12 @@ story.
 
 State schema
 ------------
-Extends ``DeepAgentState`` with ``skill_name`` and ``output_path`` as
-optional keys. Both arrive via the ``payload`` the main agent passes; the
-middleware validates presence and halts with a clear error message when
-either is missing (rather than falling back to an ambient default that
-would silently produce the wrong survey).
+Extends ``DeepAgentState`` with ``skill_name`` as an optional key,
+injected by construction when the spec is built. The middleware validates
+its presence and halts with a clear error message when missing (rather
+than falling back to an ambient default that would silently produce the
+wrong survey). Run-specific values such as the output path travel in the
+task description, not in state.
 """
 
 from __future__ import annotations
diff --git a/EvoScientist/tools/skills_manager.py b/EvoScientist/tools/skills_manager.py
index 9f8e873..5c4795f 100644
--- a/EvoScientist/tools/skills_manager.py
+++ b/EvoScientist/tools/skills_manager.py
@@ -586,7 +586,7 @@ def _parse_skill_md(skill_md_path: Path, *, source: str = "") -> SkillInfo:
         # collision guard. Coerce to the parent dir name in both cases.
         return _info(
             frontmatter.get("name") or parent.name,
-            frontmatter.get("description", "(no description)"),
+            frontmatter.get("description") or "(no description)",
             tags,
             type_=type_,
             role=str(role),
diff --git a/tests/test_experts_command.py b/tests/test_experts_command.py
index 5533ec6..9aafb73 100644
--- a/tests/test_experts_command.py
+++ b/tests/test_experts_command.py
@@ -170,6 +170,17 @@ class TestExpertToggle:
         assert ctx.channel_runtime.active_teams == ["idea-brainstorm"]
         assert any("Invited expert: idea-brainstorm" in text for text, _ in ui.lines)
 
+    async def test_invite_matches_name_case_insensitively(self):
+        """Execute honours the same case-insensitive match as completion."""
+        ctx, ui = _make_ctx()
+        with patch(
+            "EvoScientist.tools.skills_manager.list_expert_skills",
+            return_value=[_FakeSkillInfo(name="idea-brainstorm")],
+        ):
+            await ExpertCommand().execute(ctx, args=["Idea-Brainstorm"])
+        assert ctx.channel_runtime.active_teams == ["idea-brainstorm"]
+        assert any("Invited expert: idea-brainstorm" in text for text, _ in ui.lines)
+
     async def test_toggle_dismisses_when_already_invited(self):
         ctx, ui = _make_ctx(active_teams=["idea-brainstorm"])
         with patch(
diff --git a/tests/test_new_command.py b/tests/test_new_command.py
index e91ee96..c99428a 100644
--- a/tests/test_new_command.py
+++ b/tests/test_new_command.py
@@ -85,3 +85,24 @@ class TestNewCommand:
         ctx = CommandContext(agent=None, thread_id="tid", ui=ui, channel_runtime=None)
         await NewCommand().execute(ctx, [])
         ui.append_system.assert_not_called()
+
+    async def test_failed_session_start_keeps_invitations(self):
+        """A raising start_new_session leaves the current session's invites."""
+        import pytest
+
+        from EvoScientist.commands.base import ChannelRuntime, CommandContext
+        from EvoScientist.commands.implementation.session import NewCommand
+
+        ui = MagicMock()
+        ui.start_new_session = AsyncMock(side_effect=RuntimeError("gateway down"))
+        runtime = ChannelRuntime()
+        runtime.active_teams = ["idea-brainstorm"]
+        ctx = CommandContext(
+            agent=None,
+            thread_id="tid",
+            ui=ui,
+            channel_runtime=runtime,
+        )
+        with pytest.raises(RuntimeError):
+            await NewCommand().execute(ctx, [])
+        assert runtime.active_teams == ["idea-brainstorm"]
diff --git a/tests/test_resume_command.py b/tests/test_resume_command.py
index b777ee2..0c1d495 100644
--- a/tests/test_resume_command.py
+++ b/tests/test_resume_command.py
@@ -117,3 +117,50 @@ class TestResumeCommand:
         assert ctx.workspace_dir == "/keep"
         # Callback still fires with the metadata value (empty string)
         ui.handle_session_resume.assert_awaited_once_with("tid", "")
+
+
+class TestResumeClearsInvitedExperts:
+    """Invitations are session-scoped: switching threads dismisses them."""
+
+    def _runtime(self, invited):
+        from EvoScientist.commands.base import ChannelRuntime
+
+        runtime = ChannelRuntime()
+        runtime.active_teams = list(invited)
+        return runtime
+
+    async def test_switching_thread_dismisses_and_announces(self):
+        from EvoScientist.commands.implementation.session import ResumeCommand
+
+        ctx, ui = _ctx(
+            thread_id="current",
+            thread_store=FakeThreadStore(resolved_thread_id="other-tid"),
+        )
+        ctx.channel_runtime = self._runtime(["idea-brainstorm"])
+        await ResumeCommand().execute(ctx, ["other-tid"])
+        assert ctx.channel_runtime.active_teams == []
+        msgs = [c.args[0] for c in ui.append_system.call_args_list]
+        assert any(
+            "Dismissed experts on session switch: idea-brainstorm" in m for m in msgs
+        )
+
+    async def test_resuming_current_thread_keeps_invitations(self):
+        from EvoScientist.commands.implementation.session import ResumeCommand
+
+        ctx, ui = _ctx(
+            thread_id="current",
+            thread_store=FakeThreadStore(resolved_thread_id="current"),
+        )
+        ctx.channel_runtime = self._runtime(["idea-brainstorm"])
+        await ResumeCommand().execute(ctx, ["current"])
+        assert ctx.channel_runtime.active_teams == ["idea-brainstorm"]
+        msgs = [c.args[0] for c in ui.append_system.call_args_list]
+        assert not any("Dismissed experts" in m for m in msgs)
+
+    async def test_failed_resolution_keeps_invitations(self):
+        from EvoScientist.commands.implementation.session import ResumeCommand
+
+        ctx, _ui = _ctx(thread_store=FakeThreadStore())
+        ctx.channel_runtime = self._runtime(["idea-brainstorm"])
+        await ResumeCommand().execute(ctx, ["nope"])
+        assert ctx.channel_runtime.active_teams == ["idea-brainstorm"]
diff --git a/tests/test_skills_manager.py b/tests/test_skills_manager.py
index 07e2ca0..3bbb806 100644
--- a/tests/test_skills_manager.py
+++ b/tests/test_skills_manager.py
@@ -101,6 +101,22 @@ class TestParseSkillMd:
         assert result.name == "no-frontmatter-skill"
         assert result.description == "(no description)"
 
+    def test_parse_with_empty_description_value(self, tmp_path):
+        """A present-but-empty ``description:`` parses to YAML None; guard it."""
+        skill_dir = tmp_path / "empty-desc-skill"
+        skill_dir.mkdir()
+        (skill_dir / "SKILL.md").write_text(
+            """---
+name: empty-desc-skill
+description:
+---
+
+# Body
+"""
+        )
+        result = _parse_skill_md(skill_dir / "SKILL.md")
+        assert result.description == "(no description)"
+
     def test_parse_with_partial_frontmatter(self, tmp_path):
         skill_dir = tmp_path / "partial-skill"
         skill_dir.mkdir()
diff --git a/tests/test_stream_events.py b/tests/test_stream_events.py
index 55f656e..d4f6e5b 100644
--- a/tests/test_stream_events.py
+++ b/tests/test_stream_events.py
@@ -1321,6 +1321,25 @@ class TestPanelDispatchEvents:
         assert completes[0]["id"] == "ptc_task_abc12345"
         assert completes[0]["duration_ms"] == 1234
 
+    async def test_complete_event_with_null_duration_normalizes_to_zero(self):
+        agent = FakeV3Agent(
+            [
+                custom_subagent_event(
+                    {
+                        "type": "subagent",
+                        "phase": "complete",
+                        "id": "ptc_task_abc12345",
+                        "eval_id": "ci_eval_1",
+                        "duration_ms": None,
+                    }
+                ),
+            ]
+        )
+        events = await collect_events(agent)
+        completes = [e for e in events if e.get("type") == "panel_dispatch_complete"]
+        assert len(completes) == 1
+        assert completes[0]["duration_ms"] == 0
+
     async def test_error_event_becomes_panel_dispatch_error(self):
         agent = FakeV3Agent(
             [