engineering.power_factor_correction

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

With annotations covering safe-read semantics (readOnlyHint, idempotentHint, openWorldHint), the description adds real value: it discloses input constraints that must hold (real_power/voltage/frequency > 0, pf in (0,1], target_pf > current_pf) and the returned quantities. It doesn't state what happens on violating inputs, so not a 5.

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?

Front-loaded purpose, then the governing formulas, then validation constraints, return values, and a 3-phase caution—each sentence adds distinct information with no repetition or 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?

For a five-parameter calculation tool with an output schema present, the description supplies everything an agent needs: purpose, formulas, unit-bearing constraints, expected outputs, and a real-world misuse caveat. Nothing essential is missing.

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 burden, and it mostly does: it gives units (W, V, Hz) and valid ranges for all five parameters plus the relational constraint target_pf > current_pf. It does not clarify the schema's unexpected string typing for numeric inputs, which is a small remaining gap.

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?

States a specific verb+resource (compute parallel capacitance to raise the power factor of an inductive load to a target) and backs it with the governing equations Q_c=P·(tanφ₁−tanφ₂) and C=Q_c/(2π·f·V²). This lets an agent distinguish it from engineering.three_phase_power and other electrical siblings without opening the schema.

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?

Provides clear context on what the tool computes and an explicit misuse caution for three-phase systems (convert using per-phase power and capacitor terminal voltage). It doesn't name an alternative sibling or a hard when-not-to-use rule, so it falls short of 5, but the operational guidance is solid.

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