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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description goes beyond them by clarifying that it runs from measured inputs with no authentication and neither reads nor saves account data, plus it delimits what the estimate does not account for. Return format is left to 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 short sentences with the core action front-loaded. 'This estimates mechanical bias' partially restates the opening sentence, which is minor redundancy, but the caveat sentence earns its place.

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?

With an output schema present, return values need not be described, and all seven required parameters are fully documented in the schema. The description covers purpose, statelessness, and the limits of the estimate, so an agent has what it needs to call it correctly.

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% and every parameter is documented with units per unitSystem, so the schema carries the parameter semantics. The description only alludes to the input classes (piston area, rotor size, pad friction) and adds no unit or format guidance of its own, which is the expected baseline.

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 ('Estimate front brake bias') and names the exact input classes (piston area, rotor size, pad friction) that drive it. This distinguishes it clearly from sibling calculators such as calculate_corner_balance or calculate_spring_wheel_rate.

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 useful framing about what the estimate represents ('mechanical bias') and warns that tire grip, weight transfer, ABS, and balance bars still matter, which helps an agent judge the result's scope. However, it never states when to pick this tool over adjacent calculators like calculate_corner_balance, nor any prerequisite ordering.

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