check_loop_impedance

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

With no annotations, the description carries the full burden and does so well: it discloses the zero default for supply_loop_impedance_ohm, that a realistic check requires it, the conditional route check behavior of length_m, and an important limitation on trip multipliers. It omits only failure modes and units handling.

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

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

The core purpose is front-loaded in the first sentence, followed by focused parameter notes and a caveat. It is dense but every sentence carries information; no filler.

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

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

An output schema exists, so return values need not be described. For a 10-parameter calculation with zero schema descriptions, the description covers the critical parameters and one major limitation, but several parameters (mcb_curve, insulation, sizes) remain opaque.

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

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

Schema description coverage is 0%, so the description must compensate. It adds meaning for nominal_phase_voltage, supply_loop_impedance_ohm, length_m, and the separate conductor materials, but leaves mcb_curve, insulation, and both size parameters and the device rating unexplained.

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

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

The description states a specific verb and resource: 'Estimate an AC earth-fault loop length limit using resistance plus reactance.' This clearly distinguishes it from calculation siblings like calculate_voltage_drop or size_cable, though it never explicitly names an alternative.

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

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

It gives conditional guidance ('must be supplied for a realistic check', 'without it no route check is performed') and warns that B/C/D multipliers do not verify clearing time. However, it never states when to choose this over check_short_circuit or other siblings, so usage is only implied.

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