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

With no annotations, the description carries the full burden but offers only that the list can be filtered by category/interface. It does not disclose return format, pagination, or any side effects, leaving the agent without necessary behavioral context.

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, compact phrase that conveys the core functionality with no filler words. It is appropriately sized but could benefit from a bit more structure, such as a separate sentence for usage guidance.

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 the tool has no output schema and sparse annotations, the description leaves many unanswered questions: does it return full part details or summaries? Are there limits? How do the filters behave? The minimal text is insufficient for a complete understanding.

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?

The description explicitly maps 'cat' to 分類 (category) and 'interface' to インターフェイス, clarifying the bare parameter names in the schema. However, it does not explain the enum values for interface or how filters combine, so it only partially compensates for the 0% schema description coverage.

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 clearly indicates the tool provides a list of parts with filter options for category and interface, distinguishing it from part-specific operations like parts_get or parts_search. However, it lacks an explicit verb like 'list' and could more clearly define its return scope.

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 provides no guidance on when to use this tool versus alternatives such as parts_search or parts_get. It only mentions filterability, which does not help the agent choose between related list operations.

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