OilPriceAPI

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

No annotations provided, but description compensates well by disclosing return structure ('Returns high, low, average, change, and data point count') and period semantics ('day (24h), week (7d)...'). Lacks operational details like data freshness or rate limits, but covers core behavioral traits.

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?

Four efficient sentences covering purpose, usage, return values, and parameter semantics. Zero redundancy. Information is front-loaded and logically ordered.

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 2-parameter tool without output schema, description adequately covers return values (compensating for missing output schema), parameter meanings, and usage context. Complete for the tool's complexity level.

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 100% coverage (baseline 3), but description adds valuable semantic context beyond schema: maps period values to specific durations (24h, 7d, 30d, 365d) and reinforces commodity parameter usage through context.

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?

Description uses specific verb 'Get' with resource 'historical price data' and scope 'over a time period'. Clearly distinguishes from siblings like opa_get_price (current) and opa_get_forecasts (future) by emphasizing historical trends and time-based performance.

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 explicit when-to-use guidance: 'Use when the user asks about price trends, historical prices, or how a commodity has performed over time.' Lacks explicit 'when-not-to-use' or named sibling alternatives, but clear context is provided.

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