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

With no annotations, the description carries the full behavioral burden. It discloses the data sources (BitoPro, MAX), the reference rate (international USD/TWD mid-rate), and that daily historical records are returned. However, it does not mention read-only nature, authentication, rate limits, or whether the two exchanges are reported separately.

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, front-loaded sentence with no wasted clauses. It directly states the subject, scope, and outputs.

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 simple tool with one optional parameter and no output schema, the description adequately covers what is returned (latest premium percentage and daily historical records) and the source exchanges. Minor gaps remain around return shape and whether each exchange is reported separately, but the core call context is present.

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% for the single 'days' parameter, and the description adds no additional meaning about that parameter. Per the rubric, when schema coverage is high, a baseline of 3 is appropriate.

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 names a specific verb (取得/get) and a well-defined resource: USDT premium on BitoPro and MAX relative to the international USD/TWD mid-rate, plus latest premium percentage and daily history. The scope and outputs are unambiguous and no sibling tool overlaps this 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 never states when to use this tool, when not to use it, or what alternatives exist. It only describes the data returned, leaving usage context entirely to inference.

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