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

No annotations are provided, so the description must carry the full burden. It mentions '上書き' (overwrite), hinting at destructive behavior, but does not clarify whether it's a partial update, what happens to unspecified fields, authentication needs, or side effects. This is insufficient for a mutation tool.

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, front-loaded sentence that efficiently conveys the core action without unnecessary elaboration. It is concise and to the point.

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 nested patch object, the absence of annotations, and zero parameter documentation, the description is too sparse to fully inform an agent about the tool's behavior, field semantics, and possible outcomes. It covers the basic action but leaves significant gaps.

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 references 'price/procurement source' (価格/調達先) which maps to 'unit' and 'src' in the patch object, but it does not explain other fields such as cat, desc, part, keywords, footprint, or interface. Since schema coverage is 0%, the description fails to compensate for the lack of parameter documentation.

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 states 'update existing parts' (既存パーツを更新) and adds that it can overwrite prices/procurement sources of embedded parts. This is a specific verb+resource combination that distinguishes it from sibling tools like parts_add or parts_remove.

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 for updating existing parts but does not explicitly state when to use it versus alternatives like parts_add. It mentions overwriting embedded parts, which gives context, but lacks explicit exclusions or alternative tool references.

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