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

With no annotations, the description fully carries the behavioral burden and delivers thoroughly: delivery format, 30-day validity, per-gigabyte metering, price, ISP/ASN, reverse DNS, geolocation ambiguity disclosed honestly, pre-sale reachability/proxy-blacklist probing, 'no charge if no exit is verified', and x402 payment. This goes well beyond expected transparency.

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 long but front-loaded with the core transaction, then layers in ISP, geolocation, probing, and payment details. Every sentence adds substantive value; only a mild marketing sentence at the end is expendable. Not tight enough for a 5, but far from bloated.

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 the commercial side (delivery, validity, terms, exit details) and the output form (key) well. However, the undocumented required parameter undermines completeness — an agent still doesn't know how to call the tool. With no output schema, the description should clarify both input and usage, and it only covers output.

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 coverage is 0% and the sole required parameter 'exit' is never defined. The description uses 'exit' as a noun in 'If no exit is verified live' but never tells the agent what to put in the parameter (e.g., a destination URL? a target host?). This is a major omission that the description's richness does not compensate for.

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 ('Buy'), a precise resource (1 GB of French West Indies residential proxy bandwidth), and the delivery form (a key like http://buyer:KEY@host). The size, region, and residential nature distinguish it from proxy_5gb, proxy_20gb, and mobile-proxy siblings without needing to open their schemas.

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 usage context: scraping and agent traffic that need a Caribbean residential exit. It stresses that a Caribbean residential exit is rare and cannot be imitated by datacenter ranges, implying when this tool is valuable. However, it does not explicitly name alternatives or say when not to use it (e.g., for other volumes or regions).

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