get_derivatives_bars_daily_options

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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive, so the description doesn't need to repeat these. It adds useful context about return fields (OHLC, volume, open interest, implied volatility) and the Premium plan restriction. No contradiction with annotations, but rate limits or pagination are not disclosed; still, annotations cover the main safety profile.

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 with a clear Args section, but the 'Use for' list introduces some redundancy (e.g., repeating IV and implied volatility, and 'Premium only' appears twice). Despite minor repetition, every section serves a purpose and the description remains reasonably concise.

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 has an output schema, the description correctly omits detailed return formatting. It covers purpose, usage, parameters, returns, plan restriction, and a sibling alternative, making it complete for the tool's moderate complexity.

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%, but the description explains all four parameters in detail: date format and requiredness, category with concrete examples and omit-all instruction, code as issue code, and contract flag with value meanings. This fully 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 it returns daily options OHLC bars with IV, and explicitly names the sibling tool for Nikkei 225 options only, providing strong differentiation. The verb 'Returns' and resource 'options OHLC bars' are specific and unambiguous.

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?

Provides explicit usage guidance with a list of supported contexts (e.g., オプション, 日経オプション, TOPIXオプション, IV) and directly points to get_derivatives_bars_daily_options_225 for Nikkei 225 options only. Also notes the Premium plan requirement and category omission behavior.

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