> ## Documentation Index
> Fetch the complete documentation index at: https://docs.useharmonia.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Nova — read-only liaison

> Nova's skill-first read tools, evidence citations, and operator-answer contract.

## Role

Nova answers operator questions about current signals, measured engagement, posting windows, and
tenant-scoped job state. Every factual answer is bound to the actual skill and tool trace from that
invocation.

## Contract

| Property       | Value                       |
| -------------- | --------------------------- |
| ADK name       | `nova_liaison`              |
| Default model  | `gemini-3.5-flash`          |
| Input          | `LiaisonInput`              |
| Output         | `LiaisonAnswer`             |
| Runtime skills | Five filesystem ADK skills  |
| Tools          | Six bounded read-only tools |

## Skills

Nova selects exactly one of five routing skills before reading data: `trend-scan`, `signal-watch`,
`engagement-insights`, `posting-schedule`, or `job-status`.

## Tools and research

| Skill                 | Purpose                                               | Allowed tools                                                             |
| --------------------- | ----------------------------------------------------- | ------------------------------------------------------------------------- |
| `trend-scan`          | Current public startup-technology topics              | `fetch_trend_signals`, `search_trend_signals`                             |
| `signal-watch`        | Topic-specific public signals and scoped feed context | `fetch_trend_signals`, `search_trend_signals`, `get_operator_feed`        |
| `engagement-insights` | Measured published-post performance                   | `get_engagement_insights`                                                 |
| `posting-schedule`    | Evidence-based UTC window suggestions                 | `get_engagement_insights`, `get_operator_feed`, `suggest_posting_windows` |
| `job-status`          | One tenant-scoped job summary                         | `get_job_status`                                                          |

## Prompt method

Nova loads exactly one skill before a data tool, uses only successful data returned in that turn,
binds every factual claim to exact returned `evidenceId` values, displays those IDs, and separates
interpretation into uncertainty. Typed errors retain their exact code, category, safe message, and retryability. One retry is
allowed only after an explicitly retryable error; successful empty reads become `no_data`.

## Evidence and provenance

Every factual statement cites an `evidenceId` returned successfully in the current invocation.
Skill text, model memory, earlier turns, hidden errors, and unsuccessful reads are not evidence.
Typed errors and successful empty results remain explicit.

## Authority boundary

Nova cannot approve, reject, retry jobs, schedule, publish, execute, verify, create receipts, change
credentials or budgets, or mutate Firestore. Skill text, model memory, and earlier turns are not
evidence.

## Handoff

Nova returns a read-only `LiaisonAnswer` to the operator interface. It does not hand commands to the
workflow; requested state changes must enter the deterministic application path.

## Runtime enforcement

ADK callbacks record the actual skill/tool envelopes. Deterministic validation rejects wrong skills
or tools, invented evidence IDs, uncited claims, invalid retries, false `no_data`, hidden errors, and
effect-authority claims.

Monitoring receives only safe tool metadata: tool and skill names, status, duration, attempt,
stable error fields, operation, and trace. Arguments, returned data, prompts, answers, credentials,
and provider bodies are excluded.

## Implementation references

* Prompt: `agent/harmonia_agent/nova_prompt.py`
* Skills: `agent/harmonia_agent/skills/*/SKILL.md`
* Tool contracts: `agent/harmonia_agent/skills_runtime.py` and `tool_contracts.py`
* Tests: `agent/tests/test_nova_contracts.py` and `test_skills_runtime.py`