get_advance_decline_ratio

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

Annotations indicate read-only, non-destructive, idempotent behavior. The description adds context about plan restrictions ('cache-only, no API call') and threshold interpretations, which go beyond annotations. No contradictions.

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 clear sections and front-loaded key information. However, it includes a redundant 'All plans.' line and a list of supported plans that could be omitted or shortened. Slight verbosity prevents a perfect score.

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 presence of an output schema (documenting return values), the description adequately covers purpose, usage, parameters, and alternatives. It provides threshold context and sibling differentiation. A minor gap is the absence of an explicit explanation of what the advance/decline ratio represents (ratio of advancing to declining stocks), though it is implied by the name.

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?

With schema description coverage at 0%, the description compensates by specifying the expected date format (YYYY-MM-DD or YYYYMMDD) and the meaning of the 'period' parameter (trailing trading days to accumulate) along with its default value (25). This adds value beyond the schema, though some constraints (e.g., date must be a trading day) are not explicitly stated.

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 that the tool returns the advance/decline ratio over a trailing period, specifying the verb ('Return') and resource ('advance/decline ratio'). It distinguishes itself from siblings like detect_price_change and get_sector_performance by outlining when to use each.

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?

Explicitly mentions when to use this tool (for 騰落レシオ・市場過熱感 queries) and provides threshold conventions (>120 overbought, <70 oversold). It also names alternative tools (detect_price_change for daily counts, get_sector_performance for sector breakdown), offering clear guidance on when not to use this tool.

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