# validate_workflow_expressions

Validate all n8n expressions in a workflow. Checks: expression syntax ({{ }}), variable references ($json, $node, $input), node references exist, context availability. Returns specific errors with locations. Use this to catch expression errors before runtime.

Agent View of the PolicyLayer registry record for `validate_workflow_expressions`. HTML page: https://policylayer.com/tools/aegntic-aegntic-mcp/validate-workflow-expressions

## Facts

- Tool: `validate_workflow_expressions`
- Server: Obsidian Elite RAG MCP Server (`aegntic/aegntic-mcp`) — https://policylayer.com/tools/aegntic-aegntic-mcp.md
- Homepage: https://github.com/aegntic/aegntic-MCP
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "validate_workflow_expressions",
    "arguments": {}
  }
}
```

## Why validate_workflow_expressions is rated High

Validation tools that parse and evaluate expressions (even for correctness) are Execute-class because they run logic against supplied workflow content. The tool checks syntax and resolves variable/node references, meaning it actively processes and interprets expression code rather than merely reading static data. Misuse could expose internal workflow structure or be used to probe expression evaluation behavior.

From the tool's own definition: "'Validate all n8n expressions in a workflow' — triggers evaluation/parsing of workflow expressions including variable references and node context checks"

## Use case

AI agents invoke validate_workflow_expressions to trigger actions in Obsidian Elite RAG MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Obsidian Elite RAG MCP Server:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "validate_workflow_expressions": {
      "limits": [
        {
          "counter": "validate_workflow_expressions_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Obsidian Elite RAG MCP Server (134)

- `clear_all_datasets` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/clear-all-datasets.md
- `clear_dataset` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/clear-dataset.md
- `clear_expired_context_cache` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/clear-expired-context-cache.md
- `clear_graph` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/clear-graph.md
- `delete_entity_edge` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/delete-entity-edge.md
- `delete_episode` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/delete-episode.md
- `n8n_delete_execution` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/n8n-delete-execution.md
- `n8n_delete_workflow` — Destructive — https://policylayer.com/tools/aegntic-aegntic-mcp/n8n-delete-workflow.md
- `achieve_mouse_authenticity` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/achieve-mouse-authenticity.md
- `achieve_typing_authenticity` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/achieve-typing-authenticity.md
- `collaborate_with_gemini` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/collaborate-with-gemini.md
- `compile_video` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/compile-video.md
- `execute_custom_analytics_code` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/execute-custom-analytics-code.md
- `n8n_trigger_webhook_workflow` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/n8n-trigger-webhook-workflow.md
- `run_performance_benchmark` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/run-performance-benchmark.md
- `run_test_audience` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/run-test-audience.md
- `start_capture` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/start-capture.md
- `stop_capture` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/stop-capture.md
- `validate_authenticity` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/validate-authenticity.md
- `validate_workflow` — Execute — https://policylayer.com/tools/aegntic-aegntic-mcp/validate-workflow.md
- `subscribe_tier` — Financial — https://policylayer.com/tools/aegntic-aegntic-mcp/subscribe-tier.md
- `join_community` — Other — https://policylayer.com/tools/aegntic-aegntic-mcp/join-community.md
- `sequential_thinking` — Other — https://policylayer.com/tools/aegntic-aegntic-mcp/sequential-thinking.md
- `analyze_brand_performance` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/analyze-brand-performance.md
- `analyze_distributions` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/analyze-distributions.md
- `analyze_project` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/analyze-project.md
- `calculate_feature_importance` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/calculate-feature-importance.md
- `compare_datasets` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/compare-datasets.md
- `crawl_single_page` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/crawl-single-page.md
- `detect_outliers` — Read — https://policylayer.com/tools/aegntic-aegntic-mcp/detect-outliers.md
- …and 104 more: https://policylayer.com/tools/aegntic-aegntic-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=aegntic-aegntic-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/aegntic-aegntic-mcp