purchase_access

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the action ('Purchase') and outcome ('Returns API credentials on success'), but lacks details on permissions required, whether the purchase is reversible, rate limits, error conditions, or how credentials are returned (e.g., format, security). For a financial transaction tool, this leaves significant gaps in understanding its behavior.

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 two sentences that are front-loaded and efficient. The first sentence covers the core action and mechanism, while the second specifies the return value. There is no wasted language, and each sentence directly contributes to understanding the tool's function.

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 the complexity of a purchase transaction with no annotations and no output schema, the description is incomplete. It omits critical context such as error handling, credential format, confirmation steps, or integration with sibling tools like 'check_balance'. For a tool that spends credits and returns sensitive data, more comprehensive guidance is needed to ensure safe and correct usage.

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 input schema has 100% description coverage, providing clear documentation for all three parameters. The description adds no additional semantic context beyond what the schema states (e.g., it does not explain what 'API provider ID' entails or how 'amount_usd' relates to pricing tiers). With high schema coverage, the baseline score of 3 is appropriate, as the description does not compensate but also does not detract.

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 specific action ('Purchase access'), the resource ('to an API'), and the mechanism ('using your credit balance'), distinguishing it from sibling tools like 'add_credits' (which adds funds) or 'call_api' (which uses access). It explicitly mentions the outcome ('Returns API credentials on success'), making the 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 provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., having sufficient credit balance), exclusions (e.g., APIs that cannot be purchased), or direct comparisons to sibling tools like 'estimate_cost' or 'get_api_details' that might inform the purchase decision. Usage is implied but not explicitly defined.

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