etf_snapshot

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

Discloses parallel query of three tables, partial failure behavior (marks null, records caveats), and that include_realtime may be empty after hours. No annotations provided, so description carries full burden, and it excels.

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?

Efficient structure: summary line, comparison, behavior note, then args. No wasted words, front-loaded key info.

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 parameters, no annotations, and existing output schema, the description covers purpose, behavior, and parameters adequately. No missing critical context.

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 0%, but the description explains code as ETF symbol with examples and include_realtime as real-time quote inclusion with caveat. Adds significant value, though could specify code format further.

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 a complete snapshot of a single ETF, merging three TWSE tables. The verb '取得' (get) and resource 'ETF 完整概況' are specific, and it distinguishes from siblings by noting it's faster than separate calls to twse_get_dataset.

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 guidance: use when needing a comprehensive ETF overview in one call, comparing favorably to twse_get_dataset. Also notes partial failure handling (null + caveats), making it resilient.

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