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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds useful context: per-kg pricing, market-specific values, and daily movement. However, it does not explain return shape, date handling, units of currency, or behavior for invalid slugs, so the transparency is adequate but not deep.

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 two short sentences with no filler. The first sentence states the core output and unit, and the second gives parameter guidance and points to the list tool. Every sentence earns its place.

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 one-parameter lookup with no annotations and no output schema, this description covers the essential context: what the tool returns, the per-kg unit, the market/daily dimension, and how to find valid slugs. Minor omissions like exact output structure and explicit when-to-use conditions are not severe for this tool's complexity.

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 input schema only defines slug as a required string with no description. The tool description compensates by listing valid slug examples such as cabbage, daikon, onion, and recommending oroshi for the complete list, which gives the agent a concrete way to discover valid values.

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 identifies the resource: one item's wholesale price per kg, with market-level detail and daily movement. It distinguishes itself from the sibling tool oroshi by indicating that oroshi is the list. It lacks an explicit action verb such as '取得する' or '表示する', but the meaning is still concrete and specific.

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 direct routing guidance by stating '一覧は oroshi で', which tells the agent to use oroshi for the full list of slugs. It does not discuss alternatives like super_item or cost_item, but for its most closely related sibling the guidance is explicit and useful.

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