get_portfolio_performance

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and the description adds valuable behavioral context: it returns a full performance curve, statistical metrics, and benchmark comparisons with trade markers. 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?

Three concise sentences: first lists metrics, second mentions comparisons, third gives use cases. Front-loaded with essential information. No unnecessary words.

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 2 optional params, no output schema, and annotations covering safety, the description is largely complete. It could be enhanced by noting the time-series nature of the output, but the current detail supports 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?

Schema coverage is 100% with clear parameter descriptions. The description adds meaning by explaining that benchmark includes TWII, S&P500, and 散戶指數, and the default days value. This goes beyond the schema alone.

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 it retrieves portfolio performance metrics (total return, CAGR, max drawdown, Sharpe, volatility, win rate) and benchmark comparisons. It includes example questions to illustrate usage, distinguishing it from sibling tools like get_portfolio.

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-case examples ('適合回答「我的整體投資績效如何」「跑贏大盤了嗎」') that guide when to invoke. However, it does not mention when not to use or directly reference sibling alternatives, which would improve clarity.

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