Belt Drive

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

Annotations already declare readOnlyHint=true, and the description adds valuable behavioral detail by exposing the mathematical model (Eytelwein equation), the V-belt adjustment, and the pass/fail output. It does not contradict annotations and provides transparency about computational assumptions beyond the 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?

The description is a single dense block that front-loads the purpose, then provides equations and the return object—no fluff or repetition. Every sentence contributes to understanding the tool's operation.

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 no output schema, the description properly enumerates all return fields, which is essential. It also covers the core formulas and the V-belt variant, but it omits specifics about the 'pass' criterion and default friction/groove behavior, leaving minor gaps for an 8-parameter analysis tool.

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?

With 0% schema description coverage, the description must compensate, and it does: the equations map parameters to variables (D, d, C, mu, beta, P) and clarify relationships such as tension ratio and belt speed. However, 'tight_side_limit_n' is not explained, leaving a small gap for an otherwise thorough semantic mapping.

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 opens with a specific verb 'Rate a belt drive (Eytelwein/capstan)', clearly identifying the resource and the analysis type. The inclusion of governing equations and the output list further distinguishes it from mechanical siblings like 'chain_drive' or 'gear_rating'.

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 implies usage context through the belt-drive formulas and return fields, but it does not explicitly state when to choose this tool over alternatives like chain_drive, nor does it mention any exclusions. The context is clear enough for an expert to infer, but it lacks direct routing guidance.

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