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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds that the tool returns 'constituent assets and weights,' which is useful but does not go beyond what the purpose already conveys. No additional behavioral traits like pagination, defaults, or error cases are disclosed.

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 a single, direct sentence that front-loads the verb and resource. No wasted words; perfectly concise and scannable.

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 simple getter with only two parameters, strong annotations (read-only, idempotent), and a clear return concept ('assets and weights'), the description is complete enough. No output schema exists, but the description explicitly states what data will be returned, so the agent has sufficient context to invoke the tool correctly.

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 description coverage is 100%: both 'index' and 'settle' have descriptions. The tool description adds minimal extra meaning beyond the schema, such as the 'futures' context. With full schema coverage, the baseline of 3 applies; no additional parameter details are provided.

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 states exactly what the tool does with a specific verb and resource: 'Get constituent assets and weights for a futures index.' This clearly distinguishes it from sibling tools like cex_fx_get_fx_order_book or cex_fx_list_fx_contracts, which are about different data. No ambiguity.

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 implies its usage context by naming the resource (index constituents), but it does not explicitly state when to use this tool versus alternatives or when not to use it. With many fx getters/listers among siblings, explicit guidance would help, but the resource name alone makes the primary use case obvious.

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