Waveguide Cutoff

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

Beyond the readOnlyHint annotation, it discloses no-solver nature, the exact formula, evanescent vs. propagating behavior, and that below cutoff it returns attenuation α = √(k_c²−k²) as the gate signal for FDTD field probes. This is substantial behavioral context that annotations alone do not provide.

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 definition is dense but front-loaded with the core purpose and formula, then adds parameter semantics, physics, and output meaning. Given zero schema descriptions and no output schema, the length is earned; there is no filler or repetition.

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?

It covers the core call path, parameters, formula, regimes, and relationships to FDTD probes, and enumerates the full return set. A few return fields such as fidelity, band_pct, and escalate_to are listed but left to name-based inference, so with no output schema the completeness is not perfect.

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?

With schema description coverage at 0%, the description compensates fully: a_mm is broad wall, b_mm is narrow wall defaulting to a/2, mode format is TE<m><n>/TM<m><n>, eps_r appears in the formula, and freq_ghz is the probe that triggers regime/attenuation outputs. All five parameters get meaning beyond their raw names.

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 opening sentence names the exact quantity (rectangular-waveguide cutoff frequency), explicitly marks it as closed-form/no-solver, and ties it to the sibling em_fullwave_submit as the reference it is gated against. This immediately distinguishes it from the full-wave solver and the many other analysis tools.

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?

The description explicitly contrasts with 'the openEMS FDTD full-wave solve (`em_fullwave_submit`)' and states the solver is gated against this closed-form result. It also defines when the optional probe applies (returning regime and attenuation vs. FDTD probes), giving an agent clear selection and invocation context.

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