get_population

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

With no annotations, the description must carry the transparency burden. It discloses the data sources (population estimates and census) and the output format (markdown report), which is useful. However, it omits details such as error handling for invalid areas, data freshness, or whether the operation is read-only. Given the simplicity, this is adequate but not thorough.

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 concise and well-structured with Args and Returns sections. The main purpose is front-loaded, and every sentence provides necessary information. No redundant phrasing or unnecessary details.

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 single-parameter tool with an output schema, the description covers the essential aspects: what it does, how to specify the area, and the return format. It could mention edge cases like invalid area names or the time range of data, but given the simplicity and presence of an output schema, it is largely complete.

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 coverage is 0%, so the description must explain the parameter. It does so clearly, stating 'area' accepts either a region name (e.g., 東京都) or a region code (e.g., 13000), with concrete examples. This fully compensates for the lack of schema description.

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 tool retrieves population data for a region automatically, using population estimates and census data, and returns a formatted markdown report. It distinguishes itself by noting it does not require knowing the statistical table ID, which hints at an alternative but does not explicitly contrast with siblings.

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?

It implies usage: just specify a region name or code, no need for a statistical table ID. However, it does not explicitly state when to prefer this tool over alternatives like search_statistics or get_regional_data, nor does it mention when not to use it. The guidance is implicit rather than explicit.

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