Get Plans & Pricing

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

Annotations already declare readOnlyHint and openWorldHint, so the bar for additional disclosure is lower. The description adds valuable context: 'Live pricing from the API — no key required' indicates real-time data and authentication requirements. It does not mention rate limits or error behavior, but the added auth note justifies a solid score.

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 sentences: the first states the core function, the second provides usage context, and the third adds practical notes. Every sentence serves a purpose, with no redundant or unclear phrasing. It is front-loaded with the main purpose.

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, read-only tool with rich annotations and no output schema, the description fully covers what the tool does, when to use it, and auth requirements. It is complete enough for an agent to select and invoke the tool correctly without further clarification.

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, and the input schema is empty. The description therefore has no parameter details to add. Baseline for zero-param tools is 4, and the description does not introduce confusion the schema already documents everything.

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 a specific verb ('Get'), names the resource ('OilPriceAPI's current subscription plans'), and enumerates the content (monthly/yearly price, request limits, included features). This clearly distinguishes it from sibling tools like opa_get_price or opa_list_subscriptions, which focus on data or account status.

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 scenarios: 'when the user asks what an upgrade costs, which plan unlocks a gated tool... or how the tiers compare.' It also notes no key is required. However, it does not mention when not to use it or name alternative tools, so it falls short of full explicit guidance.

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