Should my agent depend on the MCP server engineer.calc/calc?

Verdict: allow — rich-slow-solo — safe to depend on As of 2026-08-15T11:28:18Z: a dated observation with receipts, not a warranty.

calc.engineer

engineer.calc/calc

88 free engineering calculators: RF link budgets, LoRa/Meshtastic, PCB, solar, homelab. Keyless.

— the operator's own registry description reported

Publisher engineer.calc · first seen 2026-08-12 · endpoint https://calc.engineer/mcp

allow

verdict

rich-slow-solo

cluster

ok_tools

answers

tools served

Dependency rating derived

allow — rich-slow-solo — safe to depend on

Cluster rich-slow-solo · distinctiveness 0.653 (unusual). Every figure is a percentile or class within the 11,094-server census — see the whole spectrum.

Reach — can an agent get to it?

answersalive_tools

latency867 ms

vs populationslow

protocolcurrent

authopen

Use — can it use it?

tools89

vs populationhigh

capabilities2

harnessA

Trust — can it rely on it?

identitysolo

servers on its host1

verifiabilityunassessed

duplicate inventoryno

drift events0

answers trueno primary

🔏 Signed receipt rr_b2204f651672d7b07e53dcda · 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

attenuator_pi attenuator_tee battery_autonomy battery_charge_time battery_life bmi_calculator capacitor_charge channel_utilization circumference compound_interest confidence_interval cooling_btu date_difference dbm_convert dipole duty_cycle_budget eirp_compliance exponent_calc fresnel_zone fspl generator_offset heatsink_cfd hex_converter impedance_match inverter_sizing lc_resonance led_resistor link_budget loan_amortization log_calc lora_airtime lora_param_optimizer lora_range_estimate lora_sensitivity mah_to_wh meshtastic_power meshtastic_range microstrip network_bandwidth noise_figure_cascade ohms_law op_amp_gain p_value pcb_layout pcb_thermal pcb_via_current percentage_calc percentage_increase power_cost power_supply_decoupling pythagorean_theorem rack_capacity raid_iops rc_filter resistor_color_code salary_to_hourly sales_tax scientific_notation sig_figs slope_calc snr_margin solar_load_audit solar_roi solar_sizing spice_simulate spice_template square_footage square_root string_sizing subnet_calculator tcp_throughput test_grade thermal_enclosure timer_555 timestamp_converter tip_calculator trace_width unit_convert ups_runtime voltage_divider voltage_drop vswr watts_to_amps wavelength_freq wire_ampacity wire_gauge wireguard_mtu zfs_capacity zfs_ram

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 check	tools passing	ok
name is clear & specific	89/89	✓
has a description	89/89	✓
description is substantive	89/89	✓
parameters are typed	89/89	✓
parameters are described	89/89	✓

89 of 89 tools graded · 89 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 calc-engineer

Capabilities: 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 (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)

date	type	what changed
2026-08-12	outcome	first probe: ok_tools

raw probe records

probed (UTC)	outcome	http	ms	protocol
2026-08-14T19:58:47Z	ok_tools	200	867	2025-06-18
2026-08-12T05:34:00Z	ok_tools	200	833	2025-06-18

Watch or embed this verdict

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/engineer.calc/calc.svg)](https://robinsaige.com/s/engineer.calc/calc)

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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