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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is fully covered. The description adds no further behavioral traits such as pagination, ordering, or rate limits, but it is consistent with the read-only nature and adds the 'unified margin lending' context.

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?

A single sentence of eight words that immediately conveys the action and scope with no filler or redundant phrasing. The description is front-loaded with the verb and resource, making it optimally concise.

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 parameterless list endpoint with strong annotations, this description is sufficient. It states exactly what is listed (all currency pairs for unified margin lending) and the return type is inferable from the 'List' verb. No output schema exists, but none is needed for such a simple tool.

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 tool has zero parameters, and the schema is trivially complete at 100% coverage. No parameter explanation is needed, so the baseline of 4 applies as per the rubric for parameterless tools.

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 the imperative 'List' with a specific resource 'all currency pairs supported for unified margin lending', clearly distinguishing it from sibling tools like cex_margin_get_uni_currency_pair which retrieves a single pair. The verb and resource are precise, leaving no ambiguity about the tool's function.

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 clear context that this tool is for listing all unified margin currency pairs, which implicitly tells when to use it versus spot or earn listing tools. However, it does not explicitly state alternatives or exclusion criteria, so it stops short of a perfect score.

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