Wave C step C3: closes E14 with the user-facing reset command. After a legitimate MCP server upgrade the sticky baseline (added in C1) becomes a stale "what the tool used to say" anchor and every subsequent post-mcp-verify advisory will re-flag the change. /security mcp-baseline-reset lets the user acknowledge the upgrade so the next call seeds a fresh baseline. New files: - scanners/mcp-baseline-reset.mjs — small CLI wrapper around clearBaseline / listBaselines. Modes: --list (read-only), --target <name>, no-args (all). Outputs JSON summary on stdout. Exit 0 always (idempotent). - commands/mcp-baseline-reset.md — dispatcher following mcp-inspect.md shape. Frontmatter: name=security:mcp-baseline-reset, sonnet model, Read/Bash/AskUserQuestion tools. 4-step body (list -> confirm scope -> execute -> confirm result). - tests/scanners/mcp-baseline-reset.test.mjs — 10 CLI tests across --list, --target, clear-all, idempotency, history preservation, and bare-positional sugar. Updated: - commands/security.md — new row in commands table after mcp-inspect. - CLAUDE.md — new commands-table row + new v7.3.0 narrative section describing the baseline schema, cumulative-drift detection, reset semantics, and the LLM_SECURITY_MCP_CACHE_FILE override. - Plugin README.md — new MCP-baseline-reset row in commands table, scanner count 12 standalone -> 13 standalone, new "MCP Description Drift (E14, v7.3.0)" subsection explaining the sticky baseline, cumulative threshold, reset semantics, and env-var override. - Root marketplace README.md — scanner count 22 -> 23 (10 orchestrated + 13 standalone), command count 19 -> 20, test count 1511 -> 1768. Wave C complete: 1738 -> 1768 tests (+30 across C1/C2/C3). Per plan, Wave C does NOT bump the plugin version — that lands at the wave-bundle release. The advisory text in post-mcp-verify already references the new command path so the user has a ready remediation step. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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| name | description | allowed-tools | model |
|---|---|---|---|
| security:mcp-baseline-reset | Reset MCP description baseline cache | Read, Bash, AskUserQuestion | sonnet |
/security mcp-baseline-reset
Reset the sticky description baseline used by post-mcp-verify.mjs for cumulative-drift detection (E14, OWASP MCP05).
Why this matters
The cache stores a per-tool baseline description plus a rolling 10-event history. Cumulative drift is measured as levenshtein(current, baseline) / max(|current|, |baseline|); when the ratio crosses the threshold (default 0.25), post-mcp-verify.mjs emits a MEDIUM mcp-cumulative-drift advisory.
After a legitimate MCP server upgrade the old baseline is stale — every subsequent call will keep tripping the advisory. Reset the baseline once to acknowledge the upgrade. The next MCP invocation will seed a fresh baseline from the new description.
Resetting removes the slow-burn detection window for that server until the new baseline is established. Only do this for upgrades you trust.
Step 1 — List current baselines
Run the listing CLI in read-only mode:
node <plugin-root>/scanners/mcp-baseline-reset.mjs --list
Parse the JSON baselines[] array. If count == 0, report "No baselines stored yet" and stop.
Step 2 — Confirm scope
Use AskUserQuestion to confirm the user's intent:
- Question: "Reset which baselines?"
- Options derived from Step 1's output:
- "All baselines (N tools)" — clears every entry
- One option per tool, e.g.
mcp__tavily__tavily_search - "Cancel" — abort
Step 3 — Execute
If the user picked all:
node <plugin-root>/scanners/mcp-baseline-reset.mjs
If the user picked a specific tool:
node <plugin-root>/scanners/mcp-baseline-reset.mjs --target <toolName>
Capture stdout JSON.
Step 4 — Confirm result
Report from the JSON response:
Cleared <cleared> baseline(s):
- <tool 1>
- <tool 2>
...
Remaining baselines: <remaining>
Add a one-line reminder: "The next MCP call to each cleared tool will seed a fresh baseline from the incoming description."
Notes
- The CLI exits 0 even when nothing was cleared (idempotent).
- History entries are preserved across reset for audit purposes.
- This command does not connect to MCP servers — it only mutates the local cache at
~/.cache/llm-security/mcp-descriptions.json.