get_advance_decline_ratio

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

Beyond the read-only and idempotent annotations, the description adds important context: cache-only (no API call), supported plans, and the overbought/oversold thresholds (>120, <70) that guide interpretation. This provides substantial behavioral and interpretive value beyond the structured annotation data.

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 structured with clear sections: purpose, usage context, thresholds, alternatives, supported plans, and parameters. Every sentence serves a purpose, and the information is front-loaded with the essential purpose.

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's simplicity, the annotations, and the presence of an output schema, the description covers all necessary aspects: purpose, when to use, parameter semantics, and plan restrictions. Nothing else is needed for correct invocation.

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 fully compensates by listing both parameters: date (End date, format YYYY-MM-DD or YYYYMMDD) and period (trailing trading days, default 25). This gives complete meaning beyond the schema's minimal type definitions.

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 returns the advance/decline ratio (騰落レシオ) over the last period trading days, with a specific verb and resource. It also distinguishes from siblings by explicitly directing daily counts to detect_price_change and sector breakdowns to get_sector_performance.

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?

Explicit when-to-use guidance is provided: 'Use for 騰落レシオ・市場過熱感 queries.' It also names alternatives with clear distinctions, and notes supported plans and cache-only behavior.

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