Second Opinion
REMOTE · SECONDOPINIONX402.COM · SCANNED SEP 22
Adversarial verification for AI agents - pay an independent skeptic per verdict in USDC via x402.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 6 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability87
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 813 tokens (~116/item across 7 items; 6 tools + 1 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 6 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the Second Opinion MCP server?
Second Opinion is a hosted endpoint at https://secondopinionx402.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · secondopinionx402.com
claude mcp add --transport http com-secondopinionx402-second-opinion 'https://secondopinionx402.com/mcp'
{
"mcpServers": {
"com-secondopinionx402-second-opinion": {
"url": "https://secondopinionx402.com/mcp"
}
}
} {
"servers": {
"com-secondopinionx402-second-opinion": {
"type": "http",
"url": "https://secondopinionx402.com/mcp"
}
}
} [mcp_servers.com-secondopinionx402-second-opinion] url = "https://secondopinionx402.com/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"com-secondopinionx402-second-opinion": {
"type": "remote",
"url": "https://secondopinionx402.com/mcp",
"enabled": true
}
}
} openclaw mcp add com-secondopinionx402-second-opinion --url 'https://secondopinionx402.com/mcp' --transport streamable-http
mcp_servers:
com-secondopinionx402-second-opinion:
url: "https://secondopinionx402.com/mcp" {
"McpServers": {
"com-secondopinionx402-second-opinion": {
"Transport": "http",
"Url": "https://secondopinionx402.com/mcp"
}
}
} assistant mcp add com-secondopinionx402-second-opinion -t streamable-http -u 'https://secondopinionx402.com/mcp'
{
"mcpServers": {
"com-secondopinionx402-second-opinion": {
"type": "http",
"url": "https://secondopinionx402.com/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 +1
- Stability: 0.97 → pass security
- 13 Aug 26 0
- The server now declares the “prompts” capability functional
- The server now declares the “resources” capability functional
- First check of Schema quality: 100 functional
- New prompt “adopt_verification_policy” functional
- New prompt “verify_before_acting” functional
- New resource “verification-policy” functional
- Server version: 0.2.1 → 0.2.2 functional
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 8 Aug 26 0
- Tool “second_opinion_quick” rewrote its description, which is the text the model reads security
- Server version: 0.2.0 → 0.2.1 functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 22 Sept 2026 · Probed https://secondopinionx402.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=secondopinionx402.com | CN=WE1,O=Google Trust Services,C=US | 19 Sept 2026 | 18 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | 9859e9c0e62cb9690e2606f81429d756 |
| SANs: secondopinionx402.com, *.secondopinionx402.com | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of secondopinionx402.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| secondopinionx402.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=31536000 |
| content-security-policy | default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; font-src 'self'; connect-src 'self'; object-src 'none'; base-uri 'self'; form-action 'self'; frame-ancestors 'none' |
| x-content-type-options | nosniff |
| x-frame-options | DENY |
| referrer-policy | strict-origin-when-cross-origin |
| permissions-policy | camera=(), microphone=(), geolocation=() |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://secondopinionx402.com/mcp | Verified | 200 | |
| http (plaintext) | http://secondopinionx402.com/mcp | HTTPS enforced | 301 | https://secondopinionx402.com/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
second_opinion_panel ~152
Three independent adversarial verifiers attack the claim through different lenses (evidence, logic, currency) and vote ($0.75, ~90s). Use for high-stakes or contested claims where a single check is not enough. Without a payment argument it returns an exact pay-per-call quote (no account, no API key).
| Name | Type | Req | Description |
|---|---|---|---|
| claim | string | yes | The single claim to verify, stated plainly. |
| context | string | – | Why this claim matters / where it came from. |
| payment | string | – | Base64 x402 payment payload built by YOUR wallet for one of the quoted accepts entries (the same string the X-PAYMENT header carries). Omit to receive a machine-readable quote. |
No output schema declared.
No examples provided.
second_opinion_pricing ~62
FREE: current tiers, prices, and exact on-chain payment requirements (accepts) for every rail — Algorand, Base, Polygon, Solana. Use this to pre-build a payment, or to discover what a verification will cost before committing.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
second_opinion_quick ~174
Independent reasoning-only check of a claim ($0.02, ~20s, no web research). Use for logic, internal consistency, and stable established knowledge (definitions, architectures, history, maths). Returns refuted/supported/inconclusive with calibrated confidence; honestly escalates to second_opinion_verify when the claim needs current-world research. Without a payment argument it returns an exact pay-per-call quote (no account, no API key).
| Name | Type | Req | Description |
|---|---|---|---|
| claim | string | yes | The single claim to verify, stated plainly. |
| context | string | – | Why this claim matters / where it came from. |
| payment | string | – | Base64 x402 payment payload built by YOUR wallet for one of the quoted accepts entries (the same string the X-PAYMENT header carries). Omit to receive a machine-readable quote. |
No output schema declared.
No examples provided.
second_opinion_result ~63
Fetch the verdict for a paid async job — polling is FREE and the verdict is already paid for. Returns status running|done|failed, with the full verdict when done.
| Name | Type | Req | Description |
|---|---|---|---|
| job_id | string | yes | The job id returned by a paid verification tool call. |
No output schema declared.
No examples provided.
second_opinion_try ~135
FREE TRIAL — no wallet, no payment, no account: the same quick reasoning-only check as second_opinion_quick, 3/day per caller (claims up to 500 chars; global daily cap applies). The trial verdict is unsigned — paid verdicts add an offline-verifiable Ed25519 receipt and live web research on the verify/panel tiers. Try the product here; use the paid tools for real work.
| Name | Type | Req | Description |
|---|---|---|---|
| claim | string | yes | The single claim to verify, stated plainly (free trial: max 500 chars). |
| context | string | – | Why this claim matters / where it came from. |
No output schema declared.
No examples provided.
second_opinion_verify ~173
Independent adversarial verification with live web research ($0.20, ~60s). A separate AI attempts to refute the claim using current sources and returns a verdict with citations. Use before irreversible commitments that depend on current-world facts. Without a payment argument it returns an exact pay-per-call quote (no account, no API key).
| Name | Type | Req | Description |
|---|---|---|---|
| claim | string | yes | The single claim to verify, stated plainly. |
| claimed_sources | array | – | URLs you relied on — they will be scrutinised, not trusted. |
| context | string | – | Why this claim matters / where it came from. |
| payment | string | – | Base64 x402 payment payload built by YOUR wallet for one of the quoted accepts entries (the same string the X-PAYMENT header carries). Omit to receive a machine-readable quote. |
No output schema declared.
No examples provided.
What is the Second Opinion MCP server?
Second Opinion is an MCP server listed in the public MCP registry as com.secondopinionx402/second-opinion. Adversarial verification for AI agents - pay an independent skeptic per verdict in USDC via x402. This page covers its hosted endpoint (https://secondopinionx402.com/mcp).
Is the Second Opinion MCP server safe to use?
Second Opinion scores 83 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the Second Opinion MCP server expose?
Second Opinion exposes 6 tools: second_opinion_quick, second_opinion_verify, second_opinion_panel, second_opinion_try, second_opinion_result, second_opinion_pricing. Their descriptions and schemas cost roughly 759 tokens of context every time the server is loaded.
Does the Second Opinion MCP server require authentication?
No. We connected to Second Opinion without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Second Opinion MCP server still maintained?
Second Opinion is still listed as active in the MCP registry. We last reached this channel on 22 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.