A/B Test Sample Size Calculator MCP
REMOTE · AB-TEST-SAMPLE-SIZE-CALCULATOR-MCP.LIPMICHAL.WORKERS.DEV
Exact A/B test sample size, duration, z-test, chi-square, Fisher-Freeman-Halton and peeking risk.
Available components
Last scanned (19 hours ago)
Scores higher than 45% of remote servers
Reachable. Last reached 4 Nov 2026.
Category Testing and QA
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
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- 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 (good).Pass
- Context-footprint check failed: tool/resource definitions use about 1091 tokens (~218/item across 5 items; 5 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 Management7
- Stability observed for 2 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage93
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 79% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 6 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.
- 4 Nov 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.
- 3 Nov 26 0
- Stability: unverified → 0.03 ▲ functional
- 2 Nov 26 63
First indexed and scored.
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 4 Nov 2026 · Probed https://ab-test-sample-size-calculator-mcp.lipmichal.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=lipmichal.workers.dev | CN=WE1,O=Google Trust Services,C=US | 2 Oct 2026 | 31 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | ebf145553d5751d20e0d3cd51e3d7a94 |
| SANs: lipmichal.workers.dev, *.lipmichal.workers.dev | ||||||
| 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 ab-test-sample-size-calculator-mcp.lipmichal.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| workers.dev. | 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://ab-test-sample-size-calculator-mcp.lipmichal.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://ab-test-sample-size-calculator-mcp.lipmichal.workers.dev/mcp | Inconclusive | 405 |
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 →
calculate_sample_size A/B test sample size calculator ~302
Exact sample size per variant for an A/B test on a conversion rate (two independent proportions): baseline rate, minimum detectable effect (relative or absolute), alpha, power, one or two-sided, several variants with optional Bonferroni, and unequal allocation. Uses the pooled/unpooled normal formula (same as R power.prop.test) and also reports the figure Evan Miller's calculator gives, so the two can be reconciled.
| Name | Type | Req | Description |
|---|---|---|---|
| allocation_ratio | number | – | Users in each variant per user in control. 1 = even split. |
| alpha | number | – | Significance level, default 0.05. |
| baseline_rate | number | yes | Control conversion rate as a proportion, for example 0.042 for 4.2%. |
| bonferroni | boolean | – | Split alpha across the variant-vs-control comparisons (Bonferroni). |
| mde | number | yes | Minimum detectable effect. Relative by default (0.10 = a 10% lift); set mde_type "absolute" for percentage points as a proportion (0.01 = 1 point). |
| mde_type | string | – | relative (default) or absolute. |
| power | number | – | Statistical power, default 0.80. |
| sided | string | – | two-sided (default) or one-sided test. |
| variants | integer | – | Number of arms including control. 2 = A/B, 3 = A/B/C. |
No output schema declared.
No examples provided.
check_peeking_risk A/B test peeking and sequential testing risk ~139
What peeking does to an A/B test: the real false positive rate if you check a fixed-horizon test K times and stop at the first p < alpha (for example about 14% at 5 looks with alpha 0.05), and the Pocock and O'Brien-Fleming group sequential boundaries (z and nominal p per look) that keep the overall rate at alpha, for up to 10 equally spaced looks.
| Name | Type | Req | Description |
|---|---|---|---|
| alpha | number | – | Significance level, default 0.05. |
| looks | integer | yes | How many times the result is checked, including the final look. Equally spaced. |
No output schema declared.
No examples provided.
estimate_test_duration A/B test duration estimator ~207
How many days an A/B test must run: from a known sample size per variant, or from baseline rate and MDE (computed as in calculate_sample_size), plus daily visitors and the share of traffic in the test. Returns exact days and the recommended whole weeks (to cover weekday effects).
| Name | Type | Req | Description |
|---|---|---|---|
| alpha | number | – | Significance level, default 0.05. |
| baseline_rate | number | – | Control conversion rate, for computing the sample size. |
| daily_visitors | number | yes | Eligible visitors per day across the whole site or page. |
| mde | number | – | Minimum detectable effect (relative by default). |
| mde_type | string | – | – |
| power | number | – | – |
| sample_size_per_variant | integer | – | Known users per arm. If omitted, give baseline_rate and mde. |
| traffic_share | number | – | Fraction of those visitors entered into the test, default 1. |
| variants | integer | – | Number of arms including control. |
No output schema declared.
No examples provided.
fisher_exact_test Fisher exact and Fisher-Freeman-Halton test ~164
Exact p-value for a contingency table of counts. 2x2: Fisher exact test (two-sided, greater or less, as R fisher.test). Larger r x c tables (for example 3 variants x converted/not, or 4 x 4 survey tables): Fisher-Freeman-Halton exact test by a network algorithm. Also returns Pearson chi-square and how many cells have expected counts below 5, so you can see when the chi-square approximation is unsafe.
| Name | Type | Req | Description |
|---|---|---|---|
| alternative | string | – | One-sided options apply to 2x2 only; greater = odds ratio above 1. |
| table | array | yes | Rows of counts, for example [[12, 488], [25, 475]] (rows = groups, columns = outcomes). |
No output schema declared.
No examples provided.
test_ab_significance A/B test significance calculator ~185
Is an A/B test result statistically significant? From visitors and conversions per group: two-proportion z-test (pooled), one or two-sided p-value, Wald confidence interval for the difference, relative lift, Pearson chi-square with and without Yates correction (R prop.test), Fisher exact p for the same 2x2 table, and a sample ratio mismatch (SRM) check against the planned split.
| Name | Type | Req | Description |
|---|---|---|---|
| alpha | number | – | Significance level, default 0.05. |
| alternative | string | – | greater = variant converts better than control. |
| control_conversions | integer | yes | – |
| control_visitors | integer | yes | – |
| expected_split | number | – | Planned share of traffic in control, for the SRM check. Default 0.5. |
| variant_conversions | integer | yes | – |
| variant_visitors | integer | yes | – |
No output schema declared.
No examples provided.
How do I install the A/B Test Sample Size Calculator MCP server?
A/B Test Sample Size Calculator MCP is a hosted endpoint at https://ab-test-sample-size-calculator-mcp.lipmichal.workers.dev/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 · ab-test-sample-size-calculator-mcp.lipmichal.workers.dev
claude mcp add --transport http theluckystrike-ab-test-sample-size-calculator-mc 'https://ab-test-sample-size-calculator-mcp.lipmichal.workers.dev/mcp'
What is the A/B Test Sample Size Calculator MCP server?
A/B Test Sample Size Calculator MCP is listed in the public MCP registry as io.github.theluckystrike/ab-test-sample-size-calculator-mcp. Exact A/B test sample size, duration, z-test, chi-square, Fisher-Freeman-Halton and peeking risk. This page covers its hosted endpoint (https://ab-test-sample-size-calculator-mcp.lipmichal.workers.dev/mcp).
Is the A/B Test Sample Size Calculator MCP server safe to use?
A/B Test Sample Size Calculator MCP scores 64 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 A/B Test Sample Size Calculator MCP server expose?
A/B Test Sample Size Calculator MCP exposes 5 tools: calculate_sample_size, estimate_test_duration, test_ab_significance, fisher_exact_test, check_peeking_risk. Their descriptions and schemas cost roughly 997 tokens of context every time the server is loaded.
Does the A/B Test Sample Size Calculator MCP server require authentication?
No. We connected to A/B Test Sample Size Calculator MCP without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the A/B Test Sample Size Calculator MCP server still maintained?
A/B Test Sample Size Calculator MCP is still listed as active in the MCP registry. We last reached this channel on 4 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.