get_rankings

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

Annotations already declare read-only and non-destructive behavior. The description adds useful behavioral details: count affects response length, and certain ranking types do not support realtime. It does not, however, mention pagination, rate limits, or sorting order, but these are less critical given the output schema exists.

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 well-structured: a clear one-line purpose, example queries, then a parameter list. Each parameter explanation is compact and informative without redundancy. It fits the information density needed for a 5-parameter tool.

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?

The description covers all parameters, gives usage examples, and notes constraints. However, it does not explicitly state which ranking types are valid for each market_country (e.g., whether TOSS_SECURITIES_TRADING_AMOUNT only applies to KR). This ambiguity is a minor gap given the output schema exists for return structure.

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 has 0% description coverage, but the description thoroughly documents every parameter: type with all enum values and Korean labels, market_country options, duration allowed values, count range and default, and exclude_investment_caution semantics. This completely compensates for the schema's lack of descriptions.

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 stock rankings with specific categories (top gainers, losers, trading amount/volume). It also gives example user queries, making the purpose immediately clear and distinct from sibling tools like get_price or get_candles.

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 explicit usage context with example queries ('stocks that went up a lot', 'stocks with high volume') and a limitation note (TOP_GAINERS/TOP_LOSERS do not support realtime). It does not explicitly name alternatives, but the sibling tool set makes the distinction clear.

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