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

With no annotations, the description carries the full burden. It discloses the payment requirement and data source, and 'Returns' implies a read-only operation. However, it omits potential failure modes, rate limits, or error behaviors, leaving some transparency gaps.

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 three concise sentences, each with clear value: purpose, payment condition, and data source. It is front-loaded with the main function and contains zero filler.

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?

The tool is simple (one required parameter) and the description covers what it returns (historical scores with dates/reasons), the payment requirement, and the data source. No output schema exists, but the return content is described. It lacks details on failure modes, but overall it is largely complete.

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 schema covers 'coin' with a clear description ('Cryptocurrency ticker symbol'), but the description adds no extra meaning about parameters. The '_meta' parameter is undocumented in both schema and description. With only 50% schema coverage and no compensatory explanation, the description does not enhance parameter understanding.

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 clearly states the verb 'Returns' and specifies the resource ('a coin's scores') and scope ('changed over time, with dates and reasons for each change'). This distinguishes it from sibling tools that likely provide current scores or rankings, making its purpose unambiguous.

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 when to use the tool (when historical score changes are needed) and mentions a key prerequisite (micropayment via MPP). However, it does not explicitly contrast with alternatives like get_tvr_score or get_full_breakdown, nor does it provide exclusions. The context is clear but not fully explicit.

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