browser_focus

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

With no annotations and a two-character description, the tool's behavior is completely undisclosed. The description does not explain any side effects, what 'focus' does in the browser context, or whether it requires element visibility or other conditions.

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 short, but this is under-specification rather than effective conciseness. It lacks any useful structure or elaboration, offering only a tautological phrase that adds no value.

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's simplicity, the description still fails to cover essential context: what focusing accomplishes, when to invoke it, or how the selector should be formatted. With dozens of sibling tools, this lack of context makes correct selection and invocation highly ambiguous.

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 description coverage is 0% and the description provides no additional meaning for the 'selector' parameter. The parameter name alone is insufficient, as the description does not clarify the expected format (e.g., CSS selector) or any constraints.

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 '聚焦元素' translates to 'Focus element', which directly restates the tool name 'browser_focus' without adding scope or distinguishing details. It specifies a verb and resource but offers no context about what focusing entails or how it differs from similar tools like browser_click or browser_hover.

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?

No guidance is provided about when to use this tool versus alternatives. There is no mention of scenarios, prerequisites, or exclusions, leaving the agent entirely without direction.

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