fetch_url

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

With no annotations, the description must carry the behavioral burden. It discloses the egress path (Singapore mobile IP) and output formats, but omits edge behaviors like redirects, error handling, or failure modes. Still, the core read-only fetch behavior is stated.

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 compact blocks: a one-sentence purpose followed by an Args list. No filler; allowed values and the default are front-loaded with the parameter definitions.

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?

For a simple two-parameter fetch tool, the essentials are present: target, format, and network path. With an output schema available, the lack of explicit return-type detail is acceptable, though examples or error behavior would round it out.

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%, so the description fully compensates: it defines url as a full http(s) URL and enumerates format values with default and meaning ('clean main content'). Both parameters are semantically clear beyond the bare string types in the schema.

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 concrete action ('Fetch a URL') with a distinctive constraint ('through a Singapore mobile IP'), clearly distinguishing it from sibling tools like search_google or rotate_ip. The resource and network context are 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?

No guidance on when to choose this over siblings; it neither names alternatives nor states conditions/exclusions. The Singapore mobile IP hint provides context, but the description does not help an agent decide between fetch_url and search_google for retrieving web content.

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