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

Annotations already establish readOnly, idempotent, non-destructive, and closed-world behavior. The description adds that it returns ratio and meters per pedal turn, but gives no further behavioral detail such as precision or output structure.

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?

Front-loads the purpose and stays compact. The input and return sentences are useful, though the incorrect wheel-diameter input makes one sentence harmful rather than helpful.

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 calculation tool with an output schema, the description is nearly sufficient, but it references a wheel diameter input that the schema does not accept. That inconsistency leaves the agent unable to know whether development per pedal turn can actually be computed.

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 100% for the two actual parameters, so the baseline would be 3. However, the description claims a third input, 'wheel diameter mm', that does not exist in the schema, and calls cog_teeth 'sprocket teeth'. This mismatch can mislead invocation.

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: compute cycling gear ratio and development per pedal turn. It clarifies the domain with 'road cycling gear analysis' but does not distinguish itself from close siblings like calculate_gear_ratio or calculate_velo_development.

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?

Gives a clear context ('Use for road cycling gear analysis') but does not say when to choose this over calculate_gear_ratio or calculate_velo_development. The pointer to list_bundles is not a usage alternative for this calculation.

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