Syl Guardian
REMOTE · GUARDIAN.SYLAI.IO
Causal check on AI agent claims, from ad-spend/ROAS lift to any decision: pass, caution or hold.
Available components
Last scanned (5 hours ago)
Scores higher than 45% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Data and Analytics
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 Security57
- 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 2 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
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- 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 Usability57
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 1573 tokens (~786/item across 2 items; 2 tools + 0 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 Management47
- Stability observed for 14 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage67
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 0% of tool parameters carry a description.Fail
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 3 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
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.
- 5 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.
- 2 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.
- 31 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.
- 29 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Oct 26 0
- The server rewrote its instructions, which are the text every model session reads security
- Tool “guardian_review” rewrote its description, which is the text the model reads security
- Schema quality: 462 → 786 ▼ functional
- “guardian_review” added an optional parameter “cate” cosmetic
- “guardian_review” added an optional parameter “config” cosmetic
- “guardian_review” added an optional parameter “estimator” cosmetic
- “guardian_review” added an optional parameter “seed” cosmetic
- “guardian_review” added an optional parameter “sensitivity” cosmetic
- 27 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.
- 24 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.
- 23 Oct 26 −1
- HSTS header: pass → fail ▼ security
- The server rewrote its instructions, which are the text every model session reads security
- Tool “guardian_review” rewrote its description, which is the text the model reads security
- Schema quality: 584 → 462 ▲ functional
- Stability: unverified → 0.03 ▲ functional
- Schema quality: good → excellent functional
- New tool “guardian_request_upload” functional
- “guardian_review” added an optional parameter “dataset_id” cosmetic
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 5 Nov 2026 · Probed https://guardian.sylai.io/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=guardian.sylai.io | CN=WE1,O=Google Trust Services,C=US | 22 Sept 2026 | 21 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | f7ba3b59062b31240e335813c617d93b |
| SANs: guardian.sylai.io | ||||||
| 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 guardian.sylai.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| io. | present | 38690 | 8 | Verified |
| sylai.io. | 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 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://guardian.sylai.io/mcp | Verified | 200 | |
| http (plaintext) | http://guardian.sylai.io/mcp | HTTPS enforced | 301 | https://guardian.sylai.io/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 →
guardian_request_upload ~173
Get a pre-signed URL for uploading a large CSV (more than ~200 rows). Use this instead of pasting rows into ``guardian_review``. Returns ``upload_url``, ``dataset_id`` and a ready-to-run ``curl`` command: run it (replace ``data.csv`` with your file; gzip is accepted with ``Content-Encoding: gzip``), then call ``guardian_review`` with ``dataset_id`` (and no ``csv``/``data``). The URL is single-use and expires after 30 minutes; the dataset is only usable by the same API key, and is single-use too: it is deleted when ``guardian_review`` reads it (even if that review fails), so request a new upload to retry. This call does not consume review quota.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
guardian_review ~1,163
Sanity-check a causal claim ("cause drove effect") before acting on it. Provide exactly one of ``csv`` (CSV text), ``data`` (list of row objects) or ``dataset_id`` (a dataset uploaded via ``guardian_request_upload``; use this for more than ~200 rows; single-use, deleted when reviewed) containing columns named by ``cause`` and ``effect``. Returns a verdict -- ``pass`` (act), ``caution`` (act carefully), or ``hold`` (do not act; the effect looks confounded or unsupported) -- with the naive correlational effect versus the confounder-adjusted causal effect and its confidence interval, the confounders adjusted for, a confidence score, a plain-English interpretation, and a recommended action, plus the estimator used and the inferred causal DAG. All numbers are deterministic statistics (never LLM-generated); the LLM may only choose an estimator id from a fixed whitelist and write the interpretation prose. Args: cause: Treatment column the claim says drives the outcome (e.g. "ad_spend"). effect: Outcome column (e.g. "new_customers"). csv: Dataset as CSV text (header row required). data: Dataset as a list of row records (alternative to ``csv``). dataset_id: ID returned by ``guardian_request_upload`` after uploading the CSV (alternative to ``csv``/``data``; for datasets above ~200 rows). Single-use: the dataset is deleted when reviewed, so re-upload to retry. known_confounders: Columns to adjust for; otherwise discovered automatically. context: Free-text business context, e.g. "Q3 promo evaluation". units: Display-only unit hints by column, e.g. {"ad_spend": "USD"}. step: A concrete treatment step (e.g. 1000 for a $1,000 spend increase) to restate the effect in business terms (cost per incremental outcome, ...). time_col: Column to order rows by for time series (autocorrelation-robust standard errors and adstock). adstock: Opt-in geometric-adstock transform for a lagged/carryover treatment. se:…
| Name | Type | Req | Description |
|---|---|---|---|
| adstock | – | – | – |
| cate | – | – | – |
| cause | string | yes | – |
| config | – | – | – |
| context | – | – | – |
| csv | – | – | – |
| data | – | – | – |
| dataset_id | – | – | – |
| effect | string | yes | – |
| estimator | – | – | – |
| known_confounders | – | – | – |
| se | string | – | – |
| seed | – | – | – |
| sensitivity | boolean | – | – |
| step | – | – | – |
| test_design | – | – | – |
| time_col | – | – | – |
| units | – | – | – |
No output schema declared.
No examples provided.
How do I install the Syl Guardian MCP server?
Syl Guardian is a hosted endpoint at https://guardian.sylai.io/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 · guardian.sylai.io
claude mcp add --transport http io-sylai-guardian 'https://guardian.sylai.io/mcp'
What is the Syl Guardian MCP server?
Syl Guardian is an MCP server listed in the public MCP registry as io.sylai/guardian. Causal check on AI agent claims, from ad-spend/ROAS lift to any decision: pass, caution or hold. This page covers its hosted endpoint (https://guardian.sylai.io/mcp).
Is the Syl Guardian MCP server safe to use?
Syl Guardian scores 65 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 Syl Guardian MCP server expose?
Syl Guardian exposes 2 tools: guardian_review, guardian_request_upload. Their descriptions and schemas cost roughly 1,336 tokens of context every time the server is loaded.
Does the Syl Guardian MCP server require authentication?
No. We connected to Syl Guardian without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Syl Guardian MCP server still maintained?
Syl Guardian is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.