get_screenshot

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

With no annotations provided, the description carries the full burden of disclosing behavior. It mentions the output is a base64 PNG, which is useful. However, it does not describe any limitations such as lack of JavaScript rendering, viewport behavior, or potential delays, leaving notable gaps for a screenshot tool.

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 extremely concise, consisting of just two short sentences. It front-loads the core purpose and then gives a clear usage condition without any unnecessary words.

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 is fairly simple, the description covers the main purpose and usage context. However, it omits parameter semantics and any behavioral caveats. Since an output schema exists, return values are likely covered, but the description overall is not fully complete for decision-making.

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 schema has 0% description coverage, and the description does not mention either parameter (url or full_page) at all. The parameter names are somewhat self-explanatory, but full_page in particular could benefit from clarification. The description provides no added 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 clearly states the tool's function: '获取网页截图（base64 PNG）' (get webpage screenshot as base64 PNG). It includes the specific resource (webpage) and output format, and it is distinct from sibling tools like scrape_url or crawl_site, which do not produce screenshots.

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 gives an explicit when-to-use condition: '当用户想看页面外观/布局时使用' (use when the user wants to see page appearance/layout). However, it does not mention alternatives or when not to use it, so it falls short of full 5-level guidance.

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