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

Annotations already declare the tool as a safe, read-only, idempotent calculation. The description adds useful behavioral context: it explains the fitment verdicts (fits / tight / rub) and that clearances must be measured on the current setup. It does not disclose assumptions such as same bolt pattern or stock suspension.

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?

Two dense but front-loaded sentences; the main comparison purpose is first, and the optional tire-field behavior is placed last. It is appropriately sized, though the long first sentence packs many outputs together.

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 an output schema and read-only annotations, the description is complete enough to call correctly: it covers the comparison, the optional tire fields, and the clearance-based verdict. Minor gaps remain around assumptions (same bolt pattern, suspension setup) and offset sign semantics.

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 coverage is 50%, and the description adds meaning mainly for the optional tire fields and the clearance measurements. It does not explain the offset sign convention or how the required wheel width/offset parameters drive the comparison, leaving several parameters to the schema names and ranges.

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 comparison task: current wheel/tire vs new wheel/tire, with outer/inner clearance, diameter, speedometer, backspacing, and tire-to-rim suitability. The purpose is clear, but it does not explicitly distinguish itself from the sibling tire_size_compare or wheel_spacer_calculator.

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?

Begins with 'Use to compare...' and gives a clear conditional: omit tire fields for a wheel-only offset comparison. It does not state when not to use it or name alternative sibling tools for overlapping cases.

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