Native TaskCreate/TaskUpdate/TaskList/TaskGet become permanently unavailable mid-session, survives /clear and a full process restart

Environment: Claude Code 2.1.207 (macOS), confirmed already latest via claude update.

What happened:
Mid-session, the native task-tracker tools (TaskCreate, TaskUpdate, TaskList, TaskGet) —
which are lazy-loaded via the ToolSearch deferred-tool mechanism — stopped being discoverable.
They were available earlier in the same session; no user action (no settings change, no
permission change) preceded the change.

Diagnosis steps taken, all inconclusive/negative:

• ToolSearch({query: "select:TaskCreate,TaskUpdate,TaskList,TaskGet"}) → "No matching deferred

tools found"

• Broader keyword ToolSearch queries ("task list create update tracker", "todo write read

tracker") surface nothing — no renamed replacement either

• claude mcp list shows no server that could plausibly back these (they're documented as

native, not MCP-backed) — rules out an MCP disconnect

• No restriction in ~/.claude/settings.json or project .claude/settings.json permissions

that would explain a deny

• A /clear did NOT restore them
• A full claude process quit + relaunch (confirmed via distinct PIDs before/after) did NOT

restore them either

• claude update confirms the CLI is already on the latest available version — rules out "a

pending update was needed"

Notably still available: TaskOutput and TaskStop (the background-task/shell-tracking
tools) remained discoverable throughout — this looks scoped specifically to the four
entity-tracker CRUD tools, not the whole Task* family.

Impact: any skill or workflow that depends on the native task tracker (e.g. this
environment's own /checkpoint skill, which recreates tracked tasks on restart) silently loses
that capability with no in-session recovery path and no clear error signal — it just stops
appearing as a callable tool.

Ask: would appreciate confirmation of whether this is a known regression, and what (if
anything) actually restores availability short of a fresh install / different machine.