Purchase a new mobile proxy

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

Description adds critical behavioral context beyond annotations: immediate charging, requirement for explicit user confirmation. Aligns with destructiveHint=true and readOnlyHint=false.

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?

Two sentences, front-loaded with purpose, includes warnings and parameter hints. Slightly dense but every sentence adds value.

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?

Covers purpose, prerequisites, parameter constraints, and return behavior. No output schema, but description states return of full connection details, which is adequate.

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?

Clarifies parameter relationships (country accepts ISO or id_country, geoid for geo-precise orders, period_days allowed values). Schema has 78% coverage, so description adds useful 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?

The description clearly states the tool purchases one or more mobile proxies and adds them to the account, using a specific verb and resource. It distinguishes from sibling tools like list_proxies and get_balance.

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 guidance: always call get_balance and get_price first, and use estimate_only for a dry-run. Does not explicitly list when not to use, but the context is clear.

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