Robin Saige we check the tools AI agents call

C6 Bank MCP

io.github.mcp-dir/c6-mcp

Connect your C6 Bank account to AI via Brazil's Open Finance: balances, statements, cards, investmen

— the operator's own registry description reported

Publisher io.github.mcp-dir · first seen 2026-08-12 · endpoint https://api.mcp.ai/p_c6

warn
verdict
farm-costume
cluster
ok_tools
answers
25
tools served

Dependency rating derived

warn
warn — costume-farm · retrieval-public ● · V1 shows its work ◐
warn — because costume-farm ●, 25 tools legible (band B) ●, no confirmed drift in 2 probes ●; not yet checked: truth (0 runs)

Cluster farm-costume · distinctiveness 0.345 (typical). Every figure is a percentile or class within the 11,094-server censussee the whole spectrum.

Does it answer? Q1 · observed
answersalive_tools
latency454 ms
vs populationslow
protocolcurrent
authopen
Can it be used? Q4 · observed
tools25
vs populationmid
capabilities1
harnessB
Did it hold when checked? Q3–Q4 · derived
identityfarm_member
servers on its host99
verifiabilityunassessed
duplicate inventoryyes
drift events0
answers trueno primary

🔏 Signed receipt rr_7abe597b165bdbb25c882d0e · ed25519 · key rs-rcpt-2026-08 — this rating is tamper-evident; an agent gets the full signature from check_server and can verify it against the published key.

Q1Does it answer?costume-farm — 2 probes ●evidence ↓
Q2What is it?retrieval-public ● evidence ↓
Q3Can it be checked?V1 shows its work ◐evidence ↓
Q4Did it hold?harness B · truth not yet run · no drift ●evidence ↓
Q5What company does it keep?farm-costume · 99 on its host (context, not verdict) ◐evidence ↓

● observed · ◐ derived · ○ reported — the verdict synthesizes Q1–Q4; Q5 is context. Methodology →

History observed

Every probe we made, oldest → newest (2 shown, 2026-08-12 → 2026-08-14). Green answered · amber answered-but-walled · red no useful answer. A gap in our cadence is a gap in coverage, not evidence about the server.

changelog (1 events)
datetypewhat changed
2026-08-12outcomefirst probe: ok_tools

What kind of tools these are derived

Verification only means something relative to a tool's NATURE — an email-sender has no "true answer", a generator has no answer key. Classification evidence: classified from tool names/descriptions/annotations WE OBSERVED. What checking applies to each kind (the full methodology →):

naturetoolsmeaning what checking applies
retrieval-public17serves public factstruth-checkable against a public source — the V-ladder applies in full
action5changes the worldno true answer exists; we check the CONTRACT (destructive/read-only/idempotent declarations, error legibility) and never fire real actions
generative1creates contentno answer key exists; disclosure + stability checks, never truth verdicts
predictive1claims about the futurescoreable only in retrospect — the archive scores yesterday's predictions against today's outcome
retrieval-private1serves the caller's own dataoutside truth-checking is impossible BY NATURE, not by failure — the operator-invited pathway applies

Tools last seen observed

authenticate connect marketplace openfinance_disconnect_bank openfinance_force_sync openfinance_get_account_balance openfinance_get_accounts_detail openfinance_get_credit_card_bill openfinance_get_item_status openfinance_get_loan_detail openfinance_list_accounts openfinance_list_categories openfinance_list_connections openfinance_list_credit_card_bills openfinance_list_investment_transactions openfinance_list_investments openfinance_list_loans openfinance_list_transactions openfinance_list_transactions_by_item openfinance_provider_status openfinance_search_bank_connectors openfinance_update_transaction_category report_bug show_version toolkit_info

Harness readiness observed

Can an agent's harness pick this tool and call it correctly? Graded on the three things an agent reads — name, description, typed parameters. Band B — usable, with rough edges.

legibility checktools passingok
name is clear & specific25/25
has a description25/25
description is substantive25/25
parameters are typed25/25
parameters are described6/256/25

25 of 25 tools graded · 25 with a captured input schema. RS-008, Tier-1 — no domain knowledge, applies to any tool. “Alive” is not the same as “usable”.

Truth checks observed

Not in the Tier-2 trade lane, or not yet checked. Tier-2 re-derives a server's answers against published primary sources — see truth checks.

Protocol conformance observed

2025-06-18
protocol version
session model
0.9.241
server version mcp-ai

Capabilities: tools

Drift observed

No confirmed drift on record. Baseline set 2026-08-14; changes appear here after human review.

raw probe records
probed (UTC) outcomehttpmsprotocol
2026-08-14T19:59:47Zok_tools2004542025-06-18
2026-08-12T05:34:59Zok_tools2005222025-06-18

Watch or embed this verdict

verdict badge

Operators: put the live verdict in your README — it updates with every census, links back here, and is a dated observation, never a warranty:

[![Robin Saige verdict](https://robinsaige.com/badge/io.github.mcp-dir/c6-mcp.svg)](https://robinsaige.com/s/io.github.mcp-dir/c6-mcp)

Depend on it? Subscribe to its change feed — outcome changes and confirmed drift, no account needed. Building on it? The full dossier as JSON — verdict, rating, truth checks, history — stable enough to gate CI on.

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