screenshot

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

With no annotations, the description discloses the dual behavior (file save vs base64 return) but lacks specifics such as image format, file overwrite behavior, error handling, and whether 'current page' means full page or visible viewport. This is basic but incomplete 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 a single sentence that front-loads the core action and explains the conditional behavior with no wasted words. It is optimally concise and well-structured.

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 tool with one param and no output schema, the description explains the main behavior but omits what is returned when 'path' is provided, the image format, and the exact scope of the screenshot. This leaves gaps that could affect correct usage.

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 already fully describes the 'path' parameter with the same meaning as the description ('图片保存路径，不传则返回图片 base64 编码'). The description adds no extra info beyond the schema's 100% coverage, so it meets the baseline but doesn't enhance it.

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 '对小程序当前页面截图' (take screenshot of current page of mini-program), using a specific verb and resource. It distinguishes itself from all sibling tools since none other involves capturing 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 explains two usage modes: passing 'path' saves to file, otherwise returns base64. This provides clear context on when to use each mode, though it doesn't mention alternatives because there are no direct siblings.

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