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

Annotations only declare readOnlyHint=true, which already establishes a safe read. The description adds genuinely useful context beyond annotations by specifying unit semantics: ratio fields are 0-1 fractions, not percentages, which prevents a real misinterpretation risk. It does not state computation windows for Sharpe beyond 3y, nor the response shape.

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 metric list is front-loaded and dense, and the unit caveat is placed immediately after it. The bilingual repetition of the same content in Japanese roughly doubles the length without adding new information, which is the main inefficiency.

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 one-parameter read-only metrics tool with 100% schema coverage, the definition covers what is returned and how to interpret ratios. However, no output schema exists, so the description is the only source of return-value structure, and it omits field names, null/missing-data behavior, and whether results are point-in-time or windowed.

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 100% and the single symbol parameter is documented with format and an example ("7203" = Toyota), so the baseline is a 3. The description's unit conventions add a small amount of meaning about how results should be read, but nothing about the parameter itself.

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 enumerates the exact technical metrics returned (52w high/low, 50/200-day MAs, volatility, turnover, drawdown, 3y return, Sharpe), which is a specific verb+resource set that clearly distinguishes it from siblings like get_key_metrics or get_returns.

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?

There is no explicit when-to-use guidance and no named alternatives, even though get_key_metrics, get_returns, get_market_cap_history and get_historical_prices overlap in scope. The agent must infer selection from the metric list alone.

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