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

No annotations are supplied, so the description carries the full behavioral burden, yet it adds nothing beyond the conversion itself. It omits that omitting the target unit returns all units and says nothing about error behavior for invalid input, though the operation is a deterministic pure computation so the risk is low.

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?

A single tight sentence that front-loads the verb and resource with zero filler. Nothing is repeated from the title and nothing extraneous is included.

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 simple three-parameter conversion tool with a fully described schema and an output schema covering return values, the description supplies enough to invoke it correctly. It could be stronger by noting the all-units default when the target is omitted.

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%, with enums and per-parameter descriptions covering the unit distinctions and the non-negative/finite constraint, so the baseline is 3. The description only restates the unit set and adds no syntax, rounding, or precision details beyond 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?

States a specific verb and resource (convert an engine power value) and enumerates the exact units handled (kW, hp, PS), which naturally distinguishes it from convert_torque, convert_distance, and the other unit converters. It does not explicitly name a sibling it is not, so it stops short of a 5.

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 never says when to reach for this tool versus its siblings or what preconditions apply; usage is only inferable from the unit list. No alternatives, no exclusions, no context cues are given.

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