engineering.ac_impedance

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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), and the description adds real behavioral content beyond them: the constraint that frequency must exceed 0, that zero means an absent element rather than a short or zero capacitance, and that a fully empty parallel combination raises an error. Only the return-shape disclosure is redundant with the output schema.

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?

Four compact sentences, front-loaded with the purpose and then parameter constraints and return values. The return-value sentence is the weakest, since the output schema already lists magnitude, phase_deg, real and imag, but it is short enough not to be costly.

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?

For a 5-parameter numeric calculator with no schema descriptions, the definition supplies units, constraints, the zero-element convention and the one error condition, which is close to everything an agent needs to call it correctly. The only shortfall is that the series-vs-parallel default and its effect are not spelled out (default is series in the schema but unstated in prose).

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 carries the full burden and does: it gives units (Hz, Ω, H, F), type and sign constraints (>0 for frequency, ≥0 Decimal strings for the passive elements), the two legal topology values, and a non-obvious semantic rule that 0 denotes an omitted element. That is meaningfully more than the bare property names in the schema.

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 opens with a specific verb+resource: computing the magnitude and phase of composite AC impedance for an R/L/C network, which tells an agent immediately what the tool computes. It does not explicitly contrast with the nearest siblings (bode_magnitude_phase, lc_resonant_frequency, rlc_time_constant), so sibling differentiation is left to inference.

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?

Usage is implied by the topology parameter and the note that a value of 0 means the element is absent, plus the explicit error case for parallel with all elements omitted. There is no statement of when to prefer this over bode_magnitude_phase or lc_resonant_frequency, which are the closest alternatives in the sibling list.

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