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

The description is straightforward and does not contradict the annotations, which already indicate a safe, read-only, idempotent operation. However, it adds no behavioral context beyond the literal action, such as response format or authentication requirements.

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 that is front-loaded with the action and resource. Every word earns its place, with no redundant information.

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 zero-parameter list operation with strong annotations, the description adequately covers the tool's purpose. The main gap is the lack of details about the response structure, but the tool name and sibling context reduce ambiguity.

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, so the input schema is trivially fully covered. Per the rubric, a baseline of 4 applies since there are no parameters to describe.

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 specific verb 'List' and identifies the resource 'currencies,' clearly stating the tool's function. However, it does not explicitly distinguish from sibling tools like cex_alpha_list_alpha_currencies or cex_mcl_list_multi_collateral_currencies, relying on the tool name's 'spot' qualifier.

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 no guidance on when to use this tool versus alternatives. There is no mention of use cases, exclusions, or related sibling tools, so the agent receives no explicit direction on selection.

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