Skill v1.0.2

version: "1.0.2" name: memtrace-impact description: "Compute the blast radius of modifying a symbol through transitive graph impact. Use when the user asks about blast radius, impact, what breaks, risk, upstream callers, downstream dependencies, or consequences of modifying a symbol, before or during source-code changes. Do not use Grep or manual reference search; Memtrace computes transitive graph impact. For a full risk-rated plan covering a multi-part change, use memtrace-change-impact-analysis."

Overview

Compute the blast radius of changing a specific symbol. Traces upstream (what depends on this) and downstream (what this depends on) through the knowledge graph to quantify risk before making modifications.

Quick Reference

Parameter types: MCP parameters are strictly typed. Numbers (depth, limit, etc.) must be JSON numbers — not strings.

Required parameters — get_impact

{ "repo_id": "memdb", "target": "validateToken", "direction": "both", "depth": 5 }

Full parameter spec for every Memtrace tool: references/mcp-parameters.md (bundled at the memtrace-skills plugin root).

Steps

1. Identify the symbol name

If you don't know the exact name:

• find_symbol(name="...") for exact identifiers
• find_code(query="...") for natural-language queries

Use the returned `name` (and optional file_path hint) — graph tools resolve by name, not internal IDs.

2. Run impact analysis

{
  "repo_id": "memdb",
  "target": "validateToken",
  "direction": "upstream",
  "depth": 5
}

3. Interpret the risk rating

4. For diff-based analysis

When you have an actual code diff, use detect_changes:

{ "repo_id": "memdb", "diff": "<unified git diff text>" }

Or pass changed_files: ["path/a.rs", "path/b.ts"] when no diff text is available.

Decision Points

Output

get_impact returns the blast radius for the target symbol:

detect_changes returns the set of symbols affected by the supplied diff / changed_files, plus the affected processes (execution flows).

Common Mistakes