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

Annotations already establish that this is read-only, idempotent, and non-destructive, so the safety profile is covered. The description adds the source URL and clarifies unit meanings, but it does not disclose any further behavioral details such as rounding or precision, though none are likely needed.

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 two compact sentences with no filler. The action and unit list are front-loaded, and the source line is a useful trust signal without bloating the text.

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?

Given the tool's simple read-only nature, the complete input schema, output schema presence, and strong annotations, the description provides everything an agent needs to select and call it correctly. No hidden side effects, auth requirements, or edge-case caveats are 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?

The schema already covers all parameters with enumsched and descriptions, so the baseline is 3. The description adds value by expanding abbreviations and clarifying that hp is mechanical horsepower and ps is metric horsepower, which goes beyond the schema's bare enum labels.

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 clearly states the action ('Convert power') and resource ('from one unit to another'), and explicitly lists the accepted units with abbreviations. This makes it immediately distinguishable from the many sibling converters (length, area, pressure, etc.).

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 intended use is implied by the description, but there is no explicit guidance about when to choose this tool over alternatives or edge cases. For a simple converter, the unit list provides enough context, but exclusions are not stated.

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