Skill

change-impact

Use before modifying a file or symbol, or when asked "what breaks if I change X?". Depth 0 — fast, no follow-up queries, returns immediately. Two modes: inline (no artifacts, default for agent-initiated use) and artifact (writes to docs/act/, triggered for human-initiated requests or Critical risk verdicts).

npx claudepluginhub act101-ai/act101 --plugin act101

Tool Access

This skill uses the workspace's default tool permissions.

Preview

**Depth:** Level 0 (Collect).

SKILL.md

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Stats

Parent Repo Stars5

Parent Repo Forks0

Last CommitApr 15, 2026

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Change Impact

Depth: Level 0 (Collect).

See ../analysis-protocol/references/protocol.md for: artifact directory structure, the investigation loop, depth levels, summary format, token budget rules, and project map structure.

Tools

Tool	Purpose	MCP call
`analyze_impact`	Blast radius (R1)	`analyze_impact` with `target: <X>`
`analyze_test_gaps`	Is the target tested? (R5)	`analyze_test_gaps`
`analyze_cycle_risk`	Is the target in a risky cycle? (R6)	`analyze_cycle_risk`

If analyze_test_gaps or analyze_cycle_risk are unavailable: run analyze_impact only. Note which tools were skipped in the verdict and caveat accordingly.

If analyze_impact is unavailable: report that and stop — no useful verdict possible.

Two Modes

Inline mode (default for agent-initiated use):

Returns the summary directly to the calling agent
Does NOT write artifacts to disk
Use when an agent needs a quick risk check before making a change

Artifact mode (for human-initiated requests, or when verdict is Critical):

Follows the full artifact protocol: create docs/act/<timestamp>/, write manifest.json, save raw/*.json, write report.md
Triggered automatically when verdict is Critical, even if initially invoked inline
Triggered by explicit user request (e.g., "analyze impact of changing X")

Risk Verdict

Compute from tool outputs:

Verdict	Criteria
Low	Blast radius < 5 files, target is tested, not in a risky cycle
Medium	Blast radius 5-15 files, OR target is untested
High	Blast radius > 15 files, OR target is untested AND in a cycle
Critical	Blast radius > 30 files, OR target is in a high-risk cycle (>50% of codebase risk surface)

When multiple criteria apply, use the highest verdict. When tools are missing, caveat the verdict: "Medium (test coverage unknown — analyze_test_gaps not available)".

Summary Format

Return this to the calling agent:

## Change Impact: <target>

**Risk: <Low / Medium / High / Critical>**
- Blast radius: N direct, M transitive dependents
- Test coverage: tested / untested / unknown (tool unavailable)
- Cycle risk: none / low / high (N% of codebase affected) / unknown (tool unavailable)

**Caution areas:** <list of highest-risk direct dependents, or "none identified">
**Suggested:** <e.g., "run tests in X before merging", "review Y for breakage", "run architecture-audit to understand full impact">

Project Map Updates

None. Change Impact reads project-map.md (workspace root) for context (chokepoints, known risky files) but does not modify it.