agent-tools (x402 + MCP + A2A directory)

Measured conclusion: Alive, not deep-tested. L2 outcome: not_attempted.

Discover x402 services, MCP servers and A2A agents by intent — agent-tools.cloud directory.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "agent-tools (x402 + MCP + A2A directory)": {
      "url": "https://agent-tools.cloud/mcp-discovery/",
      "transport": "streamable-http"
    }
  }
}

Measured tools (11)

• search

  Find x402 / MCP services matching an intent or filter set. Two usage modes (agents pick whichever fits): A. Natural-language: `search(intent="fetch tweets for @user")` B. Pure browse: `search(has_mcp=True, category="defi", top_k=10)` At least one of `intent`, `category`, `chain`, `has_mcp`, `min_confidence` must be supplied — otherwise the call is rejected (we won't dump 2300+ rows). Results are ranked by: (health=ok AND tx_30d>0) → health=ok → has-quality-signal → confidence → tx_30d → recency. So the highest-quality real-traffic services appear first. Each item includes (when available): - confidence : 0.0–1.0 x402scan quality score. - tx_30d : 30-day x402 payment count (proxy for real usage). - match_snippet : FTS snippet showing where `intent` hit ([[token]]). - match_reason : list[str] of human-readable ranking signals. - mcp_url : populated when the service exposes an MCP endpoint (you can call it directly via streamable-http). Agents should prefer items with non-null confidence and tx_30d > 0 unless the user explicitly wants experimental endpoints. Args: intent: What the agent wants to do (English or Chinese). Optional when at least one structured filter is set. Synonym expansion covers twitter↔X↔推特, whale↔巨鲸, price↔价格 etc. top_k: Max services to return (default 5, hard cap 25). max_price_usd: Upper bound on per-call price in USD. category: Filter (see `list_categories`). chain: "base", "polygon", "solana", "arbitrum", ... min_confidence: Minimum confidence (0.0–1.0). 0.8+ keeps only services x402scan rates as high-quality. has_mcp: When true, return only services with a callable MCP endpoint. Use this when the agent wants to chain another MCP server rather than perform raw HTTP+x402.

  Parameters:

  • chain
  • top_k — integer
  • intent
  • has_mcp — boolean
  • category
  • max_price_usd
  • min_confidence

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• ask_services

  Ask for the best x402/MCP services for an agent intent. This is the high-level discovery tool: it retrieves candidates from the directory, asks the configured backend LLM to rank only those candidates, and returns service cards for the selected recommendations. If the LLM is unavailable, it falls back to the directory ranker. Args: intent: Natural-language job the agent wants to accomplish. top_k: Max recommendations to return (1-10). max_price_usd: Optional per-call budget cap. category: Optional directory category filter. chain: Optional payment network filter, e.g. "base" or "solana". require_healthy: When true, only consider services marked health=ok. min_confidence: Optional x402scan quality floor (0.0-1.0). has_mcp: When true, only consider services with MCP endpoints. use_llm: Set false for deterministic retrieval-only fallback.

  Parameters:

  • intent (required) — string
  • chain
  • top_k — integer
  • has_mcp — boolean
  • use_llm — boolean
  • category
  • max_price_usd
  • min_confidence
  • require_healthy — boolean

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get

  Get full details + ready-to-paste call template for a service. Returns the service card with payment, call, quality, resource samples, and ready-to-use MCP/x402 call hints. Use this after `search` or `ask_services` before paying/calling an external service. Args: slug: Service slug as returned by `search` items.

  Parameters:

  • slug (required) — string

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• list_categories

  List all available service categories in the directory.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• stats

  High-level stats about the directory: total services, healthy count, sources.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• search_mcp_servers

  Find MCP servers in the directory. Searches the standalone MCP directory (PulseMCP / official MCP registry import) unioned with x402 services that also expose an MCP endpoint. Returns normalised entries with a ready-to-use streamable-http `call_hint.mcp.url`. Args: intent: Natural-language description of the tool/capability needed. top_k: Max servers to return (1-20). chain: Optional payment-network filter for paid MCP servers. require_healthy: When true, only return servers marked health=ok.

  Parameters:

  • chain
  • top_k — integer
  • intent
  • require_healthy — boolean

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_mcp_server

  Get the full card for one MCP server by slug.

  Parameters:

  • slug (required) — string

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• search_a2a_agents

  Find A2A agents you can delegate a task to. Args: intent: Natural-language description of the task to delegate. top_k: Max agents to return (1-20). x402_only: When true, only return agents that advertise x402 payment.

  Parameters:

  • top_k — integer
  • intent
  • x402_only — boolean

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• search_resources

  Unified search across x402 services, MCP servers and A2A agents. Args: intent: Natural-language query. protocol: Optional filter: "x402", "mcp" or "a2a". top_k: Max resources to return (1-50).

  Parameters:

  • top_k — integer
  • intent
  • protocol

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• register

  Self-register an x402 / MCP service in the agent-tools directory. Service owners and agents may submit new services here. Submissions are auto-reviewed instantly by x402 verification (no human gate): if the URL proves x402 payment support it is listed immediately and shows up in `search`; otherwise it is rejected or retried automatically. Listing is FREE. Dedup: if a service with the same canonical origin (scheme://host) already exists in the directory we return its slug instead of creating a duplicate submission. Same goes for a still-pending submission with the same origin. Rate limit: at most 5 pending submissions per client IP per 24h. Hits beyond that get `{error: rate_limited}` — try again later or email [email protected] for bulk imports. Args: url: Public HTTPS URL of the service (the x402-payable endpoint or its homepage). Required. name: Human-friendly name. Defaults to the URL hostname. description: One-paragraph description (max ~2000 chars). mcp_url: If the service speaks MCP, its streamable-http endpoint. category: Free-form (e.g. "defi", "search", "social"). Use `list_categories` to align with existing taxonomy. chains: Networks the service accepts payment on (e.g. ["base", "solana"]). price_min_usdc: Lower bound of per-call price in USDC. price_max_usdc: Upper bound of per-call price in USDC. contact: Optional email / handle the directory team can reach you on for clarifications.

  Parameters:

  • url (required) — string
  • name
  • chains
  • contact
  • mcp_url
  • category
  • description
  • price_max_usdc
  • price_min_usdc

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• scan_mcp_safety

  Check an MCP server for malware / prompt-injection lures by its endpoint URL. Give the server's streamable-http endpoint URL. Two paths: * **Already in the agent-tools directory** → returns our LATEST stored rule verdict. Every indexed server is re-scanned hourly, so you get a consistent, continuously-refreshed answer without re-probing. * **Not yet indexed** → we probe the endpoint live, statically scan its advertised tools + metadata, and return the fresh verdict. It is ADDED to the directory (so the next caller gets the stored verdict instantly) only if it answered or you supplied metadata; documentation hosts such as example.com / *.test / *.invalid are scanned but never listed. Two dimensions are reported. `verdict` is authoritative and comes from deterministic static rules — pure pattern-matching over the *advertised* text only, NO code execution. It flags the social-engineering / RCE tricks listing-spam servers use: * `curl … | bash` and `base64 -d | sh` install lures * `eval "$(curl …)"` / PowerShell `IEX(...DownloadString)` cradles * base64 blobs that decode to a shell command * bare-IP payload hosts and cheap throwaway TLDs * prompt-injection / credential-exfiltration phrasing ("ignore previous instructions", "send your .env / api key") * MCP tool-poisoning coercion — descriptions that hijack an agent's tool-calling ("always call this tool first", "before using any other tool you must…"), hidden `<IMPORTANT>` instructions, "list all API keys / include secrets in your response", and coercion to read & forward `.key`/`.pem`/`.ssh`/`.env` files Source-code-oriented rules (SQL / command / code injection) are deliberately not applied to natural-language descriptions, to avoid false positives. `llm_reference` is an advisory frontier-LLM second opinion over the same text. Because the LLM is slow it is computed LIVE on this call only and is never stored (the hourly job never runs it), so it may be null on timeout. It never overrides the rule verdict; when it is *more* severe than the rules an `advisory` note is attached as a safety-net signal. Security/defense products that merely *name* these attacks are not flagged. Args: endpoint_url: The MCP server's streamable-http URL (required). This is the identity we look up / index by. name: Optional advertised name (used when the server is new and gets added; falls back to the URL host). description: Optional description / README blurb (scanned when new). tools_text: Optional tool names + descriptions; used only if the live probe cannot fetch the server's tools/list. Returns: { verdict: "clean"|"suspicious"|"malicious", score: 0-100, reasons: [{rule, weight, snippet}], llm_reference: {model, verdict, reason, confidence} | null, advisory: str | null, slug, name, endpoint_url, source: "stored" (existing) | "new_scan" (just added), indexed: bool }

  Parameters:

  • endpoint_url (required) — string
  • name — string
  • tools_text — string
  • description — string

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

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Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.