open_url

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It only says it opens a URL and returns a success flag, but it does not mention that this launches an external browser, whether the call blocks, what happens on invalid input, or any side effects. This is minimal for an action-oriented 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 compact and well-structured with a front-loaded purpose line followed by Args and Returns sections. Every sentence earns its place, and there is no redundant or vague 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 simple two-parameter tool, purpose, arguments, and return value are covered. However, usage guidance and side-effect context are missing, and with no output schema or annotations, the description is only minimally viable rather than fully complete.

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 coverage is 0%, and the description compensates reasonably: url is defined as '完整地址' with an example (http://localhost), and browser is given explicit allowed values (default | chrome | edge | firefox). It does not explain the meaning of 'default' or error behavior, but it adds meaningful semantics 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 '用浏览器打开一个 URL' (open a URL with a browser), which is a specific verb and resource. This clearly distinguishes it from sibling tools like open_app (app opening) and screenshot (screen capture), making the tool's purpose unambiguous.

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 usage (when you need to open a URL in a browser) but gives no explicit guidance about when to use this tool versus alternatives such as open_app. No exclusions or conditions are mentioned, so the agent must infer the appropriate context.

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