getEarnAprHistory

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

Discloses key behaviors: hourly vs daily returns, descending order, range limit, and optional authentication. No annotations to contradict, and no destructive behavior to warn about.

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?

Extremely concise and well-structured with clear sections and bullet points. 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?

Given no output schema and simple query, the description covers all essential aspects: purpose, categories, ordering, range, and authentication. Sufficient for agent decision-making.

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 has 0% description coverage, and the description only mentions parameter constraints indirectly (max range). Missing details on startTime/endTime format (e.g., Unix timestamp vs ISO) and productId semantics.

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 'Query historical daily APR for a product' and distinguishes two product categories (FlexibleSaving and OnChain) with different time granularities, differentiating it from sibling tools like getEarnYieldHistory or getTokenHistoricalApr.

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?

Provides clear context: public endpoint, descending order, and max 182-day range. Lacks explicit alternatives or when-not-to-use, but the simplicity of the query makes it adequate.

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