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

Beyond readOnlyHint=true, it discloses a rich set of behavioral rules: split-adjusted intraday 52-week basis with 365 days, exclusion of IPOs under 200 trading days, exclusion of stocks with a split in the last 10 days, zero-trade and high==low exclusion, common-stocks-only universe with preferred/class and TOKYO PRO handling, no market-cap floor, sort order by trading value, and a 10-token cost.

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?

It is a dense, front-loaded paragraph where nearly every clause carries a distinct rule (universe, exclusions, sorting, cost). It is long, and the trailing Japanese one-liner partly restates the English and slightly adds bulk rather than new information.

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?

For a six-parameter screening tool with no output schema, the definition covers universe, exclusions, sort order, and cost, which is what an agent needs to call it correctly. Return-value shape is not described, though the 'sorted by trading value' note implies an ordered list, and `limit` semantics rely on the 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 coverage is 83%, so the baseline is 3. The description adds real meaning on top: it explains what omission of `market` does, clarifies that includeEtf=false implies common stocks with preferred/class shares excluded, and frames `type` and `days` in domain terms. Only `limit` is left entirely to the 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 opens with a precise verb+resource: Japanese stocks that set a 52-week high or low on the latest trading day or within `days` days. It is immediately distinguishable from siblings like get_technicals, get_market_movers, and get_market_breadth by naming the specific 52-week breakout screen.

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?

It clearly defines the use case window (latest day vs. a lookback of `days` calendar days) and states that it shares methodology with get_technicals, which helps orient the agent. It does not explicitly say when to prefer a sibling such as get_market_breadth or get_rankings, so there is no when-not guidance.

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