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 implies a read-only data retrieval operation with no side effects, but it does not explicitly state this, nor does it mention any potential limitations, data source, or update frequency. It is adequate for a simple list operation but not rich.

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 concise sentence that front-loads the main content (items, fields, cities, latest month) with no wasted words. It is appropriately sized and easy to parse.

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's simplicity (zero parameters, no output schema), the description covers the essential content: the list of items with specified fields, city list, and latest month. It could mention the output format, but for a list retrieval tool, this is sufficient. It is complete enough for an agent to understand what it returns.

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 tool has zero parameters and an empty schema, so there is nothing to document. According to the baseline for 0 parameters, this scores a 4; the description does not need to add parameter meaning since there are none.

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 the resource (daily living expense items with fields like code, name, English name, unit, category) and the action (list), also mentioning city list and latest month. It is not a tautology and provides specific content, but it does not differentiate this tool from siblings like cost_item or cost_city, which may have overlapping purposes.

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 the many sibling tools (e.g., cost_item, cost_city, data_catalog). It does not mention any context, exclusions, or alternatives, leaving the agent to infer usage from the content alone.

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