Mark Index Divergence

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

Annotations already indicate a read-only, non-destructive operation. The description adds useful behavioral context: it uses only one premiumIndex call, cross-checks with markPriceKlines vs klines, limits analysis to up to 3 symbol-pairs, and is weight-economical. This goes beyond the annotations and helps an agent understand cost and scope.

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 dense but not bloated; the first sentence packs the core behavior and constraints, and the example is useful. Minor readability could improve, but every sentence earns its place.

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 a single optional parameter and an output schema, the description covers the essential mechanism, data sources, and efficiency. It does not explain what threshold defines 'widest divergences' or how to interpret results, but the output schema likely covers return structure. Overall it is complete enough for selection and 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 0%, so the description must compensate. It provides an example invocation with limit=10, which demonstrates usage but does not explicitly define what limit controls. The single parameter is simple and the default of 20 is in the schema, making the meaning reasonably inferable.

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 identifies the tool as a mark/index divergence screener, using markPrice vs indexPrice spread and cross-checking klines. This distinguishes it from sibling screeners like funding_screener and market_overview. The purpose is specific and actionable.

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 use case is implied by the name and description: find divergence opportunities. It does not explicitly state when to prefer this tool over alternatives, nor does it mention when not to use it. The 'weight-economical' note hints at cost-conscious usage but does not provide explicit selection guidance.

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