get_market_calendar

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

No annotations are provided, so the description carries the transparency burden. It discloses the return focus (pre/regular/after-market session times), the market scope, and the date behavior. It does not mention timezone or holiday edge cases, but for a read-only lookup the core behavior is clearly stated.

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 opening sentence is front-loaded and specific, and the Args block is concise. The Korean parenthetical is slightly redundant but not harmful; overall the description is appropriately sized and well structured.

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?

With two optional parameters and an output schema present, the description covers what an agent needs to invoke the tool correctly: the meaning of each parameter and the default behavior. It leaves minor gaps around timezone and holiday handling, but these do not block correct use for typical queries.

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 description coverage is 0%, so the description is the only source of parameter meaning. It clearly defines market as 'KR' or 'US' and date as an optional YYYY-MM-DD value to center the lookup, with 'omit for today' behavior. This fully compensates for the bare schema.

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 states a specific verb and resource: 'Get market session times (pre/regular/after-market) around a given date.' This clearly distinguishes the tool from sibling market-data tools like get_current_price or get_exchange_rate, which address different 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 gives practical invocation guidance: choose 'KR' or 'US', and omit the date for today. However, it does not explicitly explain when to prefer this tool over related market-data siblings or when not to use it, so usage is implied rather than explicitly routed.

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