fetch_html

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

No annotations are provided, so the description carries the behavioral disclosure burden. It does communicate that the output is the raw HTML content, which is useful, but it does not mention potential network errors, encoding, redirects, rate limits, or whether the fetch is read-only. These are gaps, though the operation is a simple read-oriented fetch.

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 single, focused sentence with no redundant words. It front-loads the essential action and result, making it easy for an agent to parse quickly.

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 one-parameter tool with no output schema, the description is nearly complete: it identifies the input and the returned content. It could be slightly stronger with explicit guidance on choosing this tool over extract_readable, but the current wording already conveys the main distinction through 'raw HTML'.

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 description coverage is 100%, as the single 'url' parameter has a clear description. The tool description adds no additional parameter semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 action ('抓取'/fetch), the target (specified URL), and the result (raw HTML content). This distinguishes it from siblings like extract_readable, which would produce processed/readable content rather than raw HTML.

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 word '原始' (raw) implies this tool is for obtaining unprocessed HTML source rather than parsed or extracted content, but the description does not explicitly mention alternatives or specify when to choose this tool over extract_readable or query_selector. Usage context is only implied, not stated.

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