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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety and side-effect behavior are covered. The description adds useful scope by naming units and giving the mechanical horsepower conversion factor, but it does not add behavioral details such as rounding behavior, accepted unit limits, or error handling; the output schema covers the return shape.

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 description is a single front-loaded sentence with no wasted language. The conversion purpose comes first, followed by the key unit examples and sibling distinction.

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 low-complexity conversion tool, annotations and the output schema already cover safety and return details, while the description supplies the core purpose and some unit semantics. The main remaining gap is whether the listed units are exhaustive and what other power units are accepted, since the schema has no enum.

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 100%, so the baseline would be 3. The description adds meaning beyond the minimal schema descriptions by naming power units (W, kW, mechanical horsepower) and a conversion factor, which helps clarify valid from_unit and to_unit values beyond the schema examples.

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?

It uses a specific verb, 'Convert', and resource, 'power units', and names concrete units including W, kW, and mechanical horsepower. It also explicitly distinguishes itself from the x^y power calculator sibling, so an agent can tell it is a unit-conversion tool rather than exponentiation.

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 gives clear usage context for converting power units and explicitly excludes the x^y power calculator. However, it does not address other potentially confusable siblings such as calculator_ee_power, calculator_electrical_power, or calculator_physics_power, nor does it state when to choose this over a generic conversion tool.

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