后退

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

With no annotations, the description carries the transparency burden. It discloses a key side effect: '触发浏览器历史导航，可能重新加载页面' (triggers browser history navigation, may reload the page). This adds useful behavioral context beyond a bare 'go back', though it doesn't detail failure modes or prerequisites.

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 two sentences, front-loaded with the primary purpose, followed by a concise side-effect note. Every word earns its place; no filler or redundancy.

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?

The description is sufficient for a simple navigation tool with no output schema: it states the action, scope (active tab), and a relevant side effect. It does not mention behavior when there is no history, but this is a minor gap given the tool's simplicity and the schema coverage of parameters.

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 input schema covers 100% of parameters with detailed descriptions (timeout, wait_until). The tool description does not add parameter-specific meaning, but the schema already provides sufficient semantics, 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: '在活动标签页中后退到上一页历史记录' (go back to the previous page in history in the active tab). It uses a specific verb and resource, and inherently distinguishes from siblings like web_forward and web_refresh.

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 want to navigate back) but does not explicitly mention when to use vs alternatives like web_forward or web_refresh. No exclusion criteria are provided, so it remains at the 'implied usage' level.

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