Add Sprocket

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

The description reveals important behavior beyond annotations: it produces a static solid plate, uses an approximate ISO 606 tooth form, is only for fit/visualisation, and returns a bore of 0. This adds meaningful context that annotations do not provide, and nothing contradicts the readOnlyHint/destructiveHint flags.

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 structured into compact sections: purpose, parameter meanings, construction approach, and return values. Every sentence adds useful information, and despite its length, there is no filler or repetition.

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 that there is no output schema and no parameter descriptions, the description provides everything needed to call the tool correctly: parameter semantics, defaults, construction behavior, and a full return-object explanation. It even explains the mating relationship between pitch diameter and chain pitch.

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 0%, so the description fully compensates. It defines teeth with a minimum constraint, chain_pitch with a concrete example, roller_diameter as chain roller diameter, height with a default, and placement as an optional [x, y, z] mm translation. This adds substantial meaning the schema alone lacks.

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 uses a specific verb and resource: 'Add a roller-chain sprocket (ISO 606 / ANSI), built as a static solid plate.' This clearly differentiates it from sibling tools like add_gear and add_pulley by naming the exact mechanical component and standard.

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 clear context for when to use it: whenever a roller-chain sprocket is needed. It also includes a when-not limitation ('not a load-rated profile') and a follow-up command (drill the bore with `hole`), though it does not explicitly contrast it against sibling part-creation tools.

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