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

Annotations already declare this as read-only (readOnlyHint=true) and idempotent (idempotentHint=true). The description adds no additional behavioral context such as rate limits, pagination, or what 'details' includes. It simply restates the function without enriching the safety profile already covered by annotations.

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 concise sentence, front-loaded with the action ('Get') and resource ('details of a single futures contract'). Every word earns its place, with no filler or redundancy.

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 strong annotations and full schema coverage, the description is minimally adequate for tool selection. However, it lacks information about the return payload (no output schema) and any special behavior, leaving some ambiguity about what 'details' entails. It is complete enough for selection but not fully self-contained.

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 provides descriptions for both parameters ('contract' and 'settle'), covering 100% of parameters. The tool description does not add any parameter-level semantics, so a baseline score of 3 is appropriate per the rubric when schema coverage is high.

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 uses a specific verb ('Get') and clearly identifies the resource ('details of a single futures contract'), distinguishing it from list operations like cex_fx_list_fx_contracts. The word 'single' clarifies that this is for one contract, not a list.

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 does not explicitly state when to use this tool versus alternatives like cex_fx_list_fx_contracts, though 'single' implies it is for retrieving a specific contract. No exclusions or alternative guidance is provided, leaving the usage context implied rather than explicit.

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