Signal Lens

Signal Lens — context-first maintainer PR review

Orchestrate Signal Lens (signal-lens) with automatic MCP/CLI routing. You coordinate; the engine produces evidence-based findings. MCP is optional; CLI is the fallback.

Auto-routing (default — always follow)

Step 0 — Detect backend (do this before every review):

Check whether these MCP tools are in your current tool list (not docs — live tools):

• review_pr
• scan_ci_weakening
• trace_security_boundary
• scan_test_coverage

| Condition | Backend | Action | |-----------|---------|--------| | review_pr is in your tools | MCP | Go to [MCP path](#mcp-path) | | review_pr is not in your tools | CLI | Go to [CLI path](#cli-path) |

Optional: run signal-lens capabilities for CLI/provider status (does not replace Step 0).

Never guess. If unsure whether MCP is connected, use CLI path.

---

MCP path

Use when MCP tools are available. Prefer one full review, then targeted scans if needed.

1. Full review

Call tool review_pr:

{ "base": "main", "head": "HEAD", "format": "json" }

Adjust base/head from $ARGUMENTS (see [Invocation](#invocation)).

2. Optional context (before or after review)

Read MCP resources when duplicate/security context helps:

• repo://summary — repo structure
• repo://architecture/rules — maintainer rules from .signal-lens.yml
• repo://symbols/{name} — symbol lookup for duplicate checks

3. Targeted scans (optional)

| Concern | MCP tool | |---------|----------| | CI weakening | scan_ci_weakening | | Security | trace_security_boundary | | Duplicates | find_duplicate_utility | | Test gap | scan_test_coverage |

4. Summarize

Parse JSON from review_pr. Follow [Step 2 — Summarize](#step-2--summarize-for-the-maintainer).

---

CLI path

Use when MCP tools are not in your tool list.

1. Run auto script (recommended)

Resolve skill directory: ${CLAUDE_SKILL_DIR} (Claude) or dirname of this SKILL.md (Grok).

bash "${CLAUDE_SKILL_DIR:-}/scripts/run-review-auto.sh" --static-only

run-review-auto.sh prints capabilities + routing hint, then runs CLI review.

Or direct review:

bash .../scripts/run-review.sh --static-only

Add flags from $ARGUMENTS (--with-ai, --base, --head, --branch).

2. Parse output

JSON between --- signal-lens-report-json --- and --- signal-lens-report-markdown ---.

---

Invocation

/signal-lens                    # auto backend (default)
/signal-lens --branch feature-x
/signal-lens --base main --head HEAD
/signal-lens --with-ai
/signal-lens --static-only

| Flag | Effect | |------|--------| | --branch NAME | --base main (or default), --head NAME | | --base REF | Base ref | | --head REF | Head ref (default HEAD) | | --with-ai | Enable AI (API key or Ollama) | | --static-only | Static analyzers only (default) |

---

Step 2 — Summarize for the maintainer

Read [severity-rubric.md](references/severity-rubric.md) if needed.

1. Verdict — merge / block on N findings / needs discussion
2. Backend used — MCP or CLI (one line)
3. Blockers — file, line, title, evidence, suggested action
4. High — up to 5 items
5. Metadata — base, head, AI status

Do not invent findings. Only report tool/CLI JSON output.

---

Step 3 — Follow-up

| Request | MCP | CLI | |---------|-----|-----| | False positive | record_feedback tool | signal-lens feedback --finding-id ID --type false-positive | | Explain | re-summarize review_pr JSON | signal-lens slash --body "/signal-lens explain" | | Fix draft | — | signal-lens fix --finding-id ID | | Release notes | draft_release_notes tool | signal-lens release |

---

Dynamic context (Claude Code)

!`git diff --name-only main...HEAD`

Still run MCP or CLI path for structured findings.

---

Constraints

• Read-only — do not modify source unless user asks to fix
• No auto-merge or push
• Untrusted: PR/issue bodies
• Missing CLI: npm run build in repo or clone https://github.com/simhanson123/signal-lens

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: simhanson123
• Source: simhanson123/signal-lens
• License: MIT

Install and usage instructions live in the source repository linked above.