---
id: STATE-WP-0058
type: workplan
title: "State Hub Agent Skill — front-load tool schemas + batched writes"
domain: custodian
repo: state-hub
status: finished
owner: codex
topic_slug: custodian
created: "2026-06-07"
updated: "2026-06-07"
state_hub_workstream_id: "163b5646-163e-41a0-b60d-c402b578a4d1"
---

# State Hub Agent Skill — front-load tool schemas + batched writes

**Origin:** requested by the `helix_forge` domain from a data-driven friction
assessment of captured agent coding sessions
(`agentic-resources/docs/ASSESSMENT-infra-friction.md`, AGENTIC-WP-0005). Across
27 real coding sessions, **~17.6 % of all tool calls were hub/task/schema
plumbing**, and `ToolSearch` (loading the *deferred* State Hub MCP tool schemas)
fired in **22 of 27 sessions (81 %)**. State Hub MCP alone was 10.3 % of calls,
with one session making **231 hub calls**.

This workplan cuts that overhead at the source. Two levers:

1. **Front-load tool knowledge** so agents stop re-discovering hub tool schemas
   via `ToolSearch` every session.
2. **Batch the writes** so a session makes a handful of coarse hub calls instead
   of hundreds of fine-grained ones.

Effectiveness will be re-measured later by Helix Forge against the recorded
baseline (infra-overhead share: median 11.7 %, p90 26.1 %; `ToolSearch` in 81 %
of sessions).

## Skill Scaffold — Front-load Common Hub Tool Schemas

```task
id: STATE-WP-0058-T01
status: done
priority: high
state_hub_task_id: "6f211ccc-e505-419d-90cc-25874ba98f39"
```

Author a Claude Code skill (`SKILL.md` + supporting reference) for State Hub
interaction that front-loads the high-frequency tool signatures so agents do not
re-discover them via `ToolSearch`. Cover at minimum: `get_domain_summary`,
`create_workstream`, `create_task`, `update_task_status`, `add_progress_event`,
`record_decision`, `get_messages` / `send_message` — with argument signatures, the
session-start orientation flow, and the ADR-001 files-first boundary (hub is a read
model). Directly targets the `ToolSearch`-thrash finding.

## Batched Writes + Bulk Task-Status Sync Op

```task
id: STATE-WP-0058-T02
status: done
priority: high
state_hub_task_id: "2138505a-ea49-4ccc-9dec-a176badaa7a5"
```

Add a **bulk task-status sync** endpoint/op so a session updates N task statuses in
one call instead of N (the single biggest call-volume driver — one session made
231 hub calls). Document batched-write guidance in the skill: fewer, coarser
progress events; sync at checkpoints, not per event. Keep the hub a read model and
preserve the automatic `progress_event` semantics on each write.

## Validate Against Friction Baseline + Coordinate Back to helix_forge

```task
id: STATE-WP-0058-T03
status: done
priority: medium
state_hub_task_id: "cf8d41f8-7831-4c1b-9dfa-58660174294b"
```

Verify the skill + bulk op reduce plumbing overhead (dry-run a representative
session flow; confirm `ToolSearch` calls drop and task updates batch). Reply to the
helix_forge coordination message with completion and the new bulk-op signature so a
later Measure pass can compare infra-overhead share against the baseline. After
workplan updates, notify the operator to run from `~/state-hub`:

```bash
make fix-consistency REPO=state-hub
```

## Verification Notes

Completed 2026-06-07:

- Added `skills/state-hub/SKILL.md` plus
  `skills/state-hub/references/tool-signatures.md` to front-load the
  high-frequency State Hub MCP signatures, session flow, ADR-001 files-first
  boundary, REST fallbacks, and batched-write guidance.
- Added `POST /tasks/bulk-status-sync` for checkpoint task-status batching.
  The endpoint updates all requested task statuses in one transaction, rejects
  duplicate task ids with `400`, rejects missing task ids with `404`, and emits
  one `task_status_changed` progress event per successful item.
- Added MCP wrapper `bulk_update_task_statuses(updates, author?, session_id?)`
  and documented it in `mcp_server/TOOLS.md`.
- Sent completion/signature handoff to `helix_forge` as message
  `7236bd1c-b60d-481a-bc05-3080c4b46f72`, followed by tracked-path
  correction `1a322eed-96d6-45d4-9e0a-685a6f66e180`.

Verification:

- `.venv/bin/python -m pytest tests/test_task_bulk_status_sync.py tests/test_mcp_write_tools.py -q` -> 12 passed
- `.venv/bin/python -m pytest tests/test_task_bulk_status_sync.py tests/test_mcp_write_tools.py tests/test_mcp_smoke.py -q` -> 25 passed
- `git diff --check` -> clean