webfetch

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

With no annotations, the description must cover behavior. It discloses SSRF protection, ECH/DoH defaults, proxy support, default User-Agent, custom headers, and length/timeout limits. It does not mention error handling or rate limits, but provides substantial behavioral context.

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 a well-structured, front-loaded paragraph. Every sentence adds value: core purpose first, then features, then alternative tool. No redundant or unnecessary text.

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?

Given 8 parameters, no output schema, and no annotations, the description covers most critical aspects: purpose, behavior, parameters, and alternatives. It could mention return format details more explicitly, but the mention of text and Markdown conversion is sufficient.

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 100%, so baseline is 3. The description adds minimal parameter-specific insight beyond the schema, such as mentioning SOCKS5 proxy support. It does not enhance understanding of parameter usage beyond what the schema already provides.

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 fetches URL content and returns text, with automatic Markdown conversion for HTML. It also distinguishes from the download tool for binary files, ensuring no ambiguity with siblings.

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?

The description explicitly directs users to the download tool for binary files. However, it does not elaborate on when to use this tool versus other fetching tools like httpreq, leaving some usage context unaddressed.

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