Robin Saige we check the tools AI agents call

US Mortgage Calculator

com.usmortgagecalc/mortgage

US mortgage calculator and amortization API with 50-state property tax, PMI, and affordability data.

— the operator's own registry description reported

Publisher com.usmortgagecalc · first seen 2026-08-14 · endpoint https://www.usmortgagecalc.com/mcp

allow
verdict
mid-solo
cluster
ok_tools
answers
11
tools served

Dependency rating derived

allow — mid-solo — safe to depend on

Cluster mid-solo · distinctiveness 0.411 (moderate). Every figure is a percentile or class within the 11,094-server censussee the whole spectrum.

Reach — can an agent get to it?
answersalive_tools
latency336 ms
vs populationtypical
protocolcurrent
authopen
Use — can it use it?
tools11
vs populationmid
capabilities3
harnessA
Trust — can it rely on it?
identitysolo
servers on its host1
verifiabilityunassessed
duplicate inventoryno
drift events0
answers trueno primary

🔏 Signed receipt rr_d3fc0e295d9c92e29d53e35f · 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.

Tools last seen

calculate_affordability calculate_amortization calculate_mortgage calculate_pmi calculate_property_tax calculate_refinance calculate_rent_vs_buy compare_loans estimate_closing_costs get_state_mortgage_rules list_states

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 A — an agent can pick and call these reliably.

legibility checktools passingok
name is clear & specific11/11
has a description11/11
description is substantive11/11
parameters are typed11/11
parameters are described11/11

11 of 11 tools graded · 11 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
1.0.0
server version usmortgagecalc

Capabilities: prompts resources tools

Drift

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

History observed

Every probe we made, oldest → newest (1 shown, 2026-08-14 → 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
2026-08-14outcomefirst probe: ok_tools
raw probe records
probed (UTC) outcomehttpmsprotocol
2026-08-14T19:58:37Zok_tools2003362025-06-18

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/com.usmortgagecalc/mortgage.svg)](https://robinsaige.com/s/com.usmortgagecalc/mortgage)

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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