web_fetch

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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals automatic handling of redirects, cookies, and anti-bot headers, and explains the dual output modes (plain text vs raw HTML). It stops short of describing failure modes or JavaScript-rendering limitations, but the core runtime behaviors are transparent.

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 compact and well organized: one sentence for the core purpose and behavior, another for return types, then a minimal Args list. Every sentence contributes meaningful information with no fluff or repetition.

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 fetch tool with four parameters and no output schema, the description covers the essential aspects: what it fetches, how it behaves, return types, and all parameters with defaults. It doesn't mention error handling or non-HTML responses, but those are minor omissions given the straightforward use case and sibling context.

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 Args section adds meaningful semantics to every parameter: url, max_length (in chars), extract_text (strip HTML), and timeout (in seconds) with defaults. This fully compensates for the 0% schema description coverage, giving the agent a complete understanding beyond bare parameter names.

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 begins with a specific verb and resource — 'Fetch a URL' — and immediately adds distinctive behavior ('with browser-like headers to bypass basic bot protection'). It clearly distinguishes this tool from the source-code-oriented sibling tools by domain and use case.

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 clearly implies when to use the tool: when needing to retrieve web content, especially when basic bot protection may interfere. It doesn't explicitly mention when not to use it or name alternative tools, but among the listed siblings there is no competing fetch tool, so the intended context is clear.

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