Get current prices

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

Annotations already mark the tool as read-only, idempotent, and non-destructive, and the description adds meaningful behavioral detail beyond that: cost context ('cheapest way'), batching behavior, the exact return shape, the decimal-string currency behavior, null timestamps for untraded symbols, and the 404 stock-not-found error. No contradiction exists between the description and annotations.

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 and front-loaded with the core purpose, followed by usage guidance, parameter details, return shape, examples, exclusions, and error behavior. Every section earns its place; the examples are illustrative rather than redundant, and nothing is verbose or irrelevant.

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 read-only price lookup tool, the description covers all essential operational context: symbol formats, batching limits, response format options, return structure, currency/timestamp semantics, error handling, and when not to use it. Given the rich annotations and full schema coverage, nothing an agent needs to invoke it correctly is missing.

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 100%, so the baseline is 3, but the description adds useful semantic detail: it clarifies KRX symbols are 6 digits ('005930') while US symbols are tickers ('AAPL'), reinforces max 200 symbols, and states the response_format default. This goes slightly beyond the schema, warranting a 4 rather than a 3.

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 opens with a specific verb and resource: 'Get the latest traded price for one or more Korean (KRX) or US stocks.' It also differentiates itself from siblings by explicitly stating it is for current prices, not indices or bond yields, and points to tossinvest_get_market_indicator_prices for those. Examples map natural language queries to concrete symbols, reinforcing what the tool does.

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 explicitly tells the agent when to use this tool: 'This is the cheapest way to answer "what is X trading at"' and advises batching up to 200 symbols rather than looping. It also gives a clear exclusion: 'Don't use for indices (KOSPI/KOSDAQ) or bond yields — use tossinvest_get_market_indicator_prices.' This is direct when/when-not guidance.

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