Fetch Urls

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

With no annotations, the description carries the full burden and does disclose non-obvious behavior: partial-failure isolation ('单点失败不影响整体'), per-item failure reasons, and a 5-URL cap. It doesn't mention rate limits or content-type constraints, but the key operational traits are visible.

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: a one-line intent, a compact parameter list, and a clear return format. It front-loads the most critical behavioral trait (failure isolation) and avoids unnecessary filler.

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 moderately simple tool with an output schema present, the description gives enough to invoke it correctly: input shape, size limit, output format, and failure behavior. The main gap is explicit differentiation from sibling tools, but that is not fatal to correct invocation.

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 covers mode and max_chars well, giving about 67% coverage. The description adds the important missing constraint for urls: a maximum of 5 URLs, which is not in the schema. It also clarifies the per-item character limit context.

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 ('批量抓取多个网页') and the result (title + body summary per page). The batch/multiple-URL scope distinguishes it from single-page siblings like fetch_web, and the return contract is explicit.

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 implies it should be used when fetching multiple URLs at once, but it never explicitly says when to choose it over fetch_web, fetch_web_md, search_web, or fetch_rss. No exclusions or alternative routing are provided.

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