# J&L Security

> Probe-verified (tier 2 of 3). Last checked 2026-08-23. 4 of 5 capability checks passed.

- host: jandlsecurity.co.uk
- url: https://jandlsecurity.co.uk/
- category: security system installation
- type: business
- country: GB
- locations: Essex, Greater London, United Kingdom
- language: en

## Probe-verified · tier 2 of 3

Probed live on 2026-08-23 against rubric v1. 4 of 5 checks passed.

- PASS — Markdown negotiation
- fail — Markdown twin at a predictable URL
- PASS — llms.txt
- PASS — API catalog
- PASS — MCP server answers

MCP tools (from tools/list on 2026-08-23): get_company_info, list_services, get_service_details, check_service_area, get_pricing_guide, list_blog_articles

## Unverified actions

Read from the page's own content, with the wording each was drawn from. Inference is kept separate from tested facts; an agent completing the action is tier 3.

- **contact** — "Phone: 0204 538 5925"
- **query_api** — "Machine API (MCP): https://jandlsecurity.co.uk/mcp" → `https://jandlsecurity.co.uk/mcp`

## Summary

J&L Security provides installation and maintenance of alarms, CCTV, fire protection, and access control across Essex and Greater London.

## Context

3040 sites in this index share the type "business"; 1936 are transactional.

## How we grade

- tier 1 — **Declared**: The site says agents are welcome in its robots.txt. A permission, not a capability.
- tier 2 — **Probe-verified** (this site): We fetched the site and tested each signal ourselves. Dated, repeatable, re-checked on a schedule.
- tier 3 — **Behaviourally verified**: An agent completed the action end to end — booked, bought, submitted — and it worked.

## About this record

Known-Good probes sites live and publishes what was tested and when.
Method: https://knowngood.sh/about.md · Rubric: https://knowngood.sh/benchmark