buy_proxies

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

Annotations already indicate readOnlyHint=false and openWorldHint=true, but the description adds critical context: 'spends real money on the provider account' and 'only available for providers that support programmatic ordering.' This exceeds the annotation baseline without contradicting it, though it could disclose failure/refund 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?

Three tight sentences: the first states the action, the second warns about real-money impact, and the third gives availability guidance. No filler or redundant phrasing—every sentence earns its place.

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 description covers the essential context for selection and invocation: purpose, cost warning, and provider prerequisite. Combined with the output schema (present but not shown), this is sufficient for most agent decisions. Slightly limited by lack of parameter guidance, but that is captured in lower parameter semantics score.

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 description coverage is only 17% (only proxy_type has a description). The description does not compensate by explaining parameters like country, protocol, quantity, or period_days. It only mentions 'new proxies' and provider support, leaving the agent to infer parameter meanings from names and schema constraints.

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+resource combination ('Purchase new proxies') and clarifies scope by noting it's for new purchases only. It distinguishes from sibling tools like list_proxies and extend_proxies by emphasizing the monetary transaction and programmatic ordering requirement.

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: use when buying new proxies, not for listing or extending. Explicitly instructs to check list_providers first and mentions provider-specific availability, giving strong situational guidance. Does not explicitly name alternatives but the 'new' vs 'extend' distinction is implied.

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