n8n_* tools with openWorldHint:true are not registered by Claude Code

[delonsp]

Description

When using the n8n-MCP server (v2.35.2) with Claude Code, only 7 out of 20 tools are registered as available. The 13 n8n_* tools (workflow management) are completely invisible to Claude Code.

Root Cause

All 13 n8n_* tools have the MCP annotation openWorldHint: true, while the 7 registered tools do not. Claude Code appears to filter out tools with this annotation.

Registered tools (no openWorldHint):

• tools_documentation, search_nodes, get_node, validate_node, get_template, search_templates, validate_workflow

Filtered out (all have openWorldHint: true):

• n8n_create_workflow, n8n_get_workflow, n8n_update_full_workflow, n8n_update_partial_workflow, n8n_delete_workflow, n8n_list_workflows, n8n_validate_workflow, n8n_autofix_workflow, n8n_test_workflow, n8n_executions, n8n_health_check, n8n_workflow_versions, n8n_deploy_template

Evidence

When querying the MCP server directly via JSON-RPC tools/list, all 20 tools are returned:

$ echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | docker run -i --rm \
  -e MCP_MODE=stdio -e N8N_API_URL=... -e N8N_API_KEY=... \
  ghcr.io/czlonkowski/n8n-mcp:latest

# Returns 20 tools (7 without openWorldHint + 13 with openWorldHint)

But Claude Code only registers the 7 tools without openWorldHint. Using ToolSearch for any n8n_* tool returns "No matching deferred tools found".

Annotation comparison

# Registered tool example:
search_nodes: annotations={'title': 'Search Nodes', 'readOnlyHint': True, 'idempotentHint': True}

# Filtered tool example:
n8n_update_full_workflow: annotations={'title': 'Update Full Workflow', 'readOnlyHint': False, 'destructiveHint': False, 'idempotentHint': True, 'openWorldHint': True}

Suggested Fix

Consider making openWorldHint configurable via environment variable, or removing it from non-destructive read-only tools like n8n_health_check and n8n_get_workflow.

Environment

• n8n-MCP: v2.35.2 (Docker ghcr.io/czlonkowski/n8n-mcp:latest)
• Claude Code: latest (Feb 2026)
• MCP Mode: stdio
• OS: macOS Darwin 24.6.0