type: reference
status: active
timestamp: 2026-06-28
tags: [mcp, blocklist, web-tools, reference, services]

Broken / unreliable MCP servers — skip list

MCP servers that failed during 2026-06-28 testing; skip list, re-evaluate quarterly

Broken / unreliable MCP servers — skip list

Tested 2026-06-28 during compression-research session. Each MCP listed below failed in some way. Do NOT add these to .mcp.json, ~/.claude.json, .agents/*/mcp.json, or any other config without re-testing first.

Removed from Smithery toolbox 2026-06-28

These 3 were uninstalled from the chirag127 Smithery toolbox via smithery mcp remove. They will not appear in agent tool lists anymore. Do not re-add without verifying the underlying issue is resolved.

MCP	Why removed	Re-add condition
`exa` (Exa Search)	Free-tier exhausted; needs paid API key. Violates no-card-on-file rule.	Only if user funds a paid Exa key
`ghostrouter-ghostrouter-web`	Crypto micropayment paywall (USDC per call). Hard veto.	Never re-add
`pinkpixel-dev-web-scout-mcp` (Web Scout / DDG)	Returns empty results consistently for valid queries that worked on other engines.	Test 5 queries return non-empty; if all pass, re-add

Re-add via: smithery mcp add <name> after verifying.

Web search MCPs — broken / conditional (still in toolbox)

MCP	Failure mode	Verdict	Re-eval condition
`mcp__chirag127__tavily_*`	”Connection not found: tavily” until ToolSearch loaded schemas; even then rate-limited on first call	Conditional — works after ToolSearch load + once-per-day rate window	Try after 24h cooldown
`mcp__chirag127__brave_brave_web_search`	”Connection not found: brave” — same ToolSearch pattern	Conditional — works after ToolSearch	Try after 24h

Web search MCPs — working

MCP	Notes
`mcp__chirag127__keenable-web-search_search_web_pages`	Default. Returned 9-10 quality hits per query; filters by date; arxiv + blog mix
`mcp__chirag127__linkupplatform-linkup-mcp-server_linkup-search`	Deep search worked; returns 97KB+ payloads with full content from multiple sources
`mcp__chirag127__oevortex-ddg-search_web-search`	Returned 8 hits cleanly; fast
`mcp__searxng__searxng_web_search`	Failed earlier with JSON-parse error but reportedly works; retry
`mcp__fetch__fetch`	Reliable for single-URL markdown extraction
`mcp__chirag127__parallel-search_web_search_preview`	Untested this session — try next
`mcp__chirag127__axel-belfort-web-search_web_search_query`	Untested
`mcp__chirag127__apify_apify--rag-web-browser`	Untested
`mcp__chirag127__ref-tools-ref-tools-mcp_ref_search_documentation`	Docs search — different role, not generic web

Security flags — working but with known vulnerabilities

MCP	CVE / Advisory	Risk	Mitigation
`open-websearch` (npm pkg in `~/.claude.json`)	CVE-2026-42260 — SSRF	Bracketed IPv6 literals + non-resolving hostnames bypass `isPrivateOrLocalHostname` check in `fetchWebContent` tool. SSRF non-blind (response streamed to MCP caller).	Kept active per user decision 2026-06-28. Don’t use it on untrusted URLs. Patch when upstream releases fix. Check `npm view open-websearch versions` quarterly.

Order to try web search (fastest to most-thorough)

mcp__chirag127__keenable-web-search_search_web_pages — default
mcp__chirag127__oevortex-ddg-search_web-search — fast fallback
mcp__chirag127__linkupplatform-linkup-mcp-server_linkup-search (depth: deep) — when need comprehensive
mcp__fetch__fetch — when you have a specific URL
Retry tavily / brave after a ToolSearch load + 24h cooldown

Other broken / abandoned MCPs noted

MCP	Issue
`DesignSync`	Disconnected mid-session (system-reminder confirmed) — server died

Re-evaluation cadence

Test quarterly:

Try the conditionally-broken ones (tavily, brave, exa) with fresh API keys
Try pinkpixel-ddg to see if results came back
Try searxng with a fresh JSON-parse retry

If any becomes reliable for 5+ test queries, remove from this list and add to the working set in .agents/claude/rules/never-use-native-web-tools.md.

Edit on GitHub · Back to index