List residential proxy plans

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful domain context beyond annotations: residential is billed per GB in bundles, larger bundles are cheaper per GB, and price_id links to purchase or top-up. It does not describe pagination or the exact return shape, but the billing behavior is well disclosed.

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 short sentences, front-loaded with what the tool returns followed by the billing rationale and the price_id role. Every sentence carries distinct information with no filler.

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?

With no output schema, the description does meaningful work by noting the return includes plans with price per GB and a price_id, plus the tiered pricing behavior. It stops short of describing the full response shape or whether results are ordered, but it covers enough for an agent to use the tool correctly.

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 takes zero parameters, so per the rubric the baseline is 4. The description mentions price_id, but that is a return-value field rather than an input parameter, so there is no parameter semantics to add.

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?

States a specific verb and resource ('Returns the residential proxy plans') plus the key attribute (price per GB). It distinguishes itself from the sibling get_price by explicitly stating that these prices replace get_price for residential, so an agent can route correctly without opening a schema.

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?

Gives a clear routing rule — use these plans for residential pricing rather than get_price — and explains why (billed by traffic volume, not rental period). It does not state explicit exclusions or point to purchase/top-up siblings by name, but the alternative is named with a clear condition.

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