browser_count

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

With no annotations, the description carries the full burden for behavioral disclosure. It does not mention return format (e.g., a number), edge cases like zero matches, selector validity, or any side effects. '统计元素数量' is too terse to convey meaningful behavioral traits beyond the basic action.

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 with zero wasted words, but it is under-specified to the point of bordering on a tautology. It lacks structure that would help an agent understand scope or expected behavior, so it is not appropriately sized for effective use.

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 has one parameter, no output schema, and no annotations, the description should provide at least basic usage context. It does not mention return value, selector type (CSS vs other), or any exceptions. For a simple count tool, this is incomplete though not completely useless.

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 does not compensate. The 'selector' parameter is not explained in the description, leaving its format or semantics entirely to inference. The description adds no meaning beyond the schema's bare type declaration.

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 '统计元素数量' (Count the number of elements) clearly states the core action and resource. It distinguishes from sibling tools like browser_get_text or browser_click, but it does not explicitly mention the selector parameter or that the count applies to matching elements, so it lacks full specificity.

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 provides no guidance on when to use this tool versus alternatives, nor any mention of prerequisites or context. It merely states what the tool does without any usage notes.

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