calc.engineer

eirp compliance

eirp_compliance

Checks EIRP (Effective Isotropic Radiated Power) compliance against regional regulatory limits for LoRa and Meshtastic operation. Computes EIRP from transmit power, antenna gain, and cable loss, then compares against FCC (US, 36 dBm), ETSI (EU, 16.15 dBm), ACMA (Australia, 30 dBm), IC (Canada, 36 dBm), and ARIB (Japan, 13 dBm) limits. Returns compliance status, margin in dB, and a warning message if over the limit. Critical for Meshtastic deployments using aftermarket high-gain antennas which can easily exceed ETSI/JP limits. Accepts tx_power and antenna_gain from meshtastic_range for chain validation.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`region`	No	Regulatory region for EIRP limit lookup. FCC_US: 36 dBm, ETSI_EU: ~16 dBm, ACMA_AU: 30 dBm, IC_CA: 36 dBm, JP: 13 dBm.	FCC_US
`tx_power_dbm`	Yes	Conducted transmit power at the radio output in dBm. Typical LoRa: 14-22 dBm.
`cable_loss_db`	No	Coaxial cable and connector loss in dB. Set 0 for devices with integrated antennas.
`antenna_gain_dbi`	Yes	Antenna gain in dBi. Stock Meshtastic antennas: 2-3 dBi. External: 6-10+ dBi.
`custom_limit_dbm`	No	Custom EIRP limit in dBm. Only used when region is 'custom'.

Output Schema

TableJSON Schema

Name	Required	Description
`warning`	Yes	Warning message if non-compliant, or empty string if compliant.
`eirp_dbm`	Yes	Calculated EIRP in dBm: tx_power + antenna_gain - cable_loss.
`compliant`	Yes	True if EIRP is at or below the regional limit.
`limit_dbm`	Yes	Regional EIRP limit in dBm.
`margin_db`	Yes	Margin below the limit in dB. Positive = compliant, negative = over limit.
`eirp_watts`	Yes	Calculated EIRP converted to watts.
`limit_watts`	Yes	Regional EIRP limit converted to watts.
`region_name`	Yes	Human-readable region name.

TDQS

A4.3/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It discloses the return values: compliance status, margin in dB, and warning message. It explains the computation logic (computes EIRP from tx power, antenna gain, cable loss). There is no mention of destructive behavior, but as a computation tool, that is appropriate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single dense paragraph that efficiently conveys all needed information without redundancy. It is front-loaded with the main purpose. Minor improvement: could be broken into bullet points for readability, but current structure is effective and earns its sentences.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 5 parameters, all described, and an output schema (though details not in provided context), the description covers the return values and usage context. It mentions chain validation with meshtastic_range, which provides operational context. It is sufficient for an agent to understand and invoke the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 100% coverage with descriptions for all parameters. The description adds extra meaning beyond the schema: it notes that tx_power and antenna_gain come from meshtastic_range for chain validation, and provides typical values (e.g., 'Stock Meshtastic antennas: 2-3 dBi'). This aids parameter selection.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool checks EIRP compliance against regional regulatory limits for LoRa and Meshtastic operation. It specifies computation of EIRP from transmit power, antenna gain, and cable loss, and comparison against multiple regional limits. This distinguishes it from sibling tools, which are all different calculators.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly mentions it is 'Critical for Meshtastic deployments using aftermarket high-gain antennas' and that it accepts parameters from meshtastic_range for chain validation. This provides clear context on when to use the tool, though it does not explicitly state when not to use it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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TDQS

A3.9/5.0

Disambiguation4/5

Despite 89 tools, each has a clearly distinct purpose with detailed descriptions that often reference related tools. Overlap exists (e.g., multiple LoRa/RF tools), but the descriptions are sufficient to distinguish them. Some confusion possible among similar-sounding tools like attenuator_pi and attenuator_tee, but the descriptions explicitly compare them.

Naming Consistency4/5

Consistent underscore-separated lowercase naming. Most tools follow a verb_noun pattern (e.g., capacitor_charge, wire_gauge) or noun_noun (power_cost). Minor inconsistencies such as 'bmi_calculator' vs 'solar_sizing' but overall predictable.

Tool Count2/5

89 tools is far too many for a single MCP server. This scope is more appropriate for multiple specialized servers. The sheer number will slow agent selection and increase cognitive load, reducing coherence.

Completeness3/5

Covers many domains (RF, solar, PCB, networking, math, etc.) but lacks depth in some areas (e.g., no three-phase power, no airflow calculations). Some domains have comprehensive coverage (LoRa/Meshtastic), but others feel incomplete for the tool count.

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