getPremiumIndexPriceKline

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

With no annotations, the description carries full burden. It discloses that data is returned in reverse chronological order and the output format (5-element array). It does not mention rate limits or error handling, but for a read-only kline endpoint, the coverage is good. A minor gap is lack of mention of pagination behavior.

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 bullet points and bold headings, making it scannable. It is front-loaded with the core purpose. However, the 'Agent hint' at the end is redundant with earlier content, adding slight unnecessary length.

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 kline query tool with 6 parameters and no output schema, the description covers purpose, usage context, output format, ordering, authentication, and differentiation from similar tools. It lacks explicit parameter descriptions but the standard nature of kline parameters partially compensates. Overall, it is fairly complete.

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?

The input schema has 0% description coverage, so the description must add meaning. However, it does not explicitly explain any parameters (e.g., start, end, limit). The meaning of symbol and interval is implied by the endpoint type, but start/end and limit are standard but not described. The 'Agent hint' is vague and doesn't compensate. This is a significant gap.

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 queries historical premium index price klines and explains they represent the basis between mark and index price for funding rate calculations. It explicitly distinguishes from sibling tools like getMarketKline, getMarkPriceKline, and getIndexPriceKline.

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 cases (analyzing funding rate basis, researching mark-index relationship, building charts) and explicitly states when not to use it (for trading/mark/index price candles) with references to alternative endpoints. Also notes that no authentication is required.

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