fetch_url

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

No annotations are provided, so the description must fully disclose behavior. It explains the fetch, browser impersonation, Markdown conversion, and error conditions. However, it lacks details on potential issues like rate limiting, authentication requirements, or behavior on invalid URLs, which would improve 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 well-structured with a clear summary line followed by argument and return documentation. The list of impersonation values is lengthy but informative. It earns its place, though it could be slightly more concise.

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 the tool's simplicity, the presence of an output schema (which we assume documents return structure), and the description's coverage of all parameters and behavior (including conversion to Markdown), the description is complete for an AI agent to use 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 input schema has no descriptions (coverage 0%), but the description provides extensive semantics for all four parameters, including default values, examples for impersonate, and explanation of max_chars behavior. This adds significant meaning beyond 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?

The description states 'Fetch web content from a URL with browser camouflage,' which clearly defines the tool's action and resource. It also specifies a unique feature (browser camouflage), making it easily distinguishable even without sibling tools.

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?

While no explicit when-to-use or when-not-to-use guidance is given, the description thoroughly explains the tool's purpose and parameters. The absence of sibling tools reduces the need for alternatives comparison, so the description is clear enough for an AI agent to decide.

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