# MCP Tool Surface Drift Check

> MCP Tool Surface Drift Check is a paid API for AI agents from agents.daedalusdevelopmentgroup.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Compares a pinned MCP tool baseline against a live server's tool surface to detect additions, removals, renames, schema changes, scope broadening, and injection-suspect text in descriptions.

## Facts

- Endpoint: POST https://agents.daedalusdevelopmentgroup.com/v1/mcp/drift-check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mcp-tool-surface-drift-check-2cee1307
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QAh22fVbE3T0FPqdwV2IC

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability mcp-tool-surface-drift-check-2cee1307 -d '<json body>'
```

Example prompt: Check whether my MCP server at https://my-mcp-server.example.com has drifted from the baseline I pinned last week — flag any tools that were added, removed, renamed, or had their descriptions changed, and call out anything that looks like prompt injection.

## When to prefer this

Choose this endpoint when you need to programmatically verify that an MCP server's tool surface has not changed since a known-good baseline was pinned — especially useful in CI/CD pipelines before deploying agent configurations, after third-party MCP server updates, or as a periodic security monitor to catch prompt injection or unauthorized scope expansion in tool definitions. Prefer this over manual diffing or generic API comparison tools because it is purpose-built for MCP tool fingerprint semantics, understands SSE-aware and well-known fallback discovery, and produces a signed verdict with injection-suspect text detection.

## Known failure modes

- Live MCP server unreachable — network error or timeout returned
- Baseline fingerprints malformed or missing required fields — validation error
- MCP server does not support JSON-RPC tools/list — fallback to well-known endpoint attempted
- SSE stream unavailable — connection error returned
- Inline current_tools payload malformed — parse error returned
- Payment not processed — 402 response before drift check executes

## How this service works

MCP tool-surface drift check: compare a pinned baseline (tool fingerprints) against the live surface (JSON-RPC tools/list, SSE-aware, well-known fallback) or an inline current_tools. Flags added/removed/renamed tools, description/schema changes, scope broadening, and injection-suspect text in new/changed descriptions. Signed verdict. $0.01.

## Output

A signed drift verdict object indicating whether the live MCP tool surface matches the pinned baseline, with categorized lists of added, removed, and renamed tools, details of description and schema changes, scope-broadening alerts, and flags for injection-suspect text in new or modified descriptions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input",
  "output"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": true
  },
  "output": {
   "type": "object",
   "required": [
    "type",
    "example"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "ok": true
    }
   },
   "additionalProperties": true
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mcp-tool-surface-drift-check-2cee1307/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agents.daedalusdevelopmentgroup.com](https://www.zero.xyz/host/agents.daedalusdevelopmentgroup.com/llms.txt)