get_derivatives_bars_daily_futures

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds valuable context beyond annotations by disclosing the Premium-only access requirement and specifying the output includes OHLC, volume, and open interest, which is not otherwise communicated.

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 efficiently structured with a title line, use-case keywords, returns summary, plan note, and a clear Args list. It is slightly longer than the ideal but every section earns its place, and the parameter list is essential given the zero schema coverage.

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 tool is simple with only 3 parameters and an output schema exists. The description covers the data returned (OHLC, volume, open interest), the Premium requirement, and all parameters thoroughly. Minor omissions like timezone handling or date edge cases are not critical given the available output schema.

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 must fully explain parameters. It does so excellently: date format (YYYYMMDD or YYYY-MM-DD), category examples (Futures225, FuturesTOPIX) with 'omit for all', and contract_flag meaning (0=all, 1=front, 2=back). This adds complete meaning beyond 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 clearly states the tool provides daily futures OHLC bars, listing specific contract types (日経先物, TOPIX先物, etc.) and explicitly distinguishes it from sibling tools like options and equities by the 'futures' keyword. The resource and data type are 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?

The description provides explicit 'Use for' keywords (先物, 日経先物, etc.) and notes the Premium plan requirement, giving clear context for when to invoke this tool. However, it does not explicitly mention when not to use it or name alternatives (e.g., the options tool), though sibling names imply this.

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