browser_snapshot

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

With no annotations provided, the description carries the full burden. It discloses that the output is a 'compact' snapshot (not full DOM), that refs are 'stable' (persist across interactions), and that it provides the targets for other tools. It implies a non-destructive read operation. It does not mention errors or performance, but for a simple snapshot tool this is adequate.

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?

Two sentences with zero redundancy. The core action is front-loaded, and the second sentence delivers the key detail about ref markers that drives usage. Every word earns its place.

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 tool has no output schema, so the description must convey the return value. It states it returns a compact accessibility snapshot with stable ref markers, which is sufficient for an agent to know how to consume it and pass refs to other tools. It omits a precise structure, but given the tool's simplicity, this is a minor gap.

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 tool has zero parameters, so schema coverage is trivially 100%. Per the rubric, a baseline of 4 is appropriate because there is nothing to clarify about parameters. The description does not need to add parameter meaning.

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 a specific action ('Capture'), a clear resource ('compact accessibility snapshot of the current page'), and uniquely identifies its output (ref markers) that serve as targets for sibling tools. This distinguishes it from browser_take_screenshot (visual) and browser_console_messages (logs), making the 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?

While it does not explicitly name alternative tools, the sentence 'Interactive elements carry stable [ref=eN] markers used as targets for other tools' implies the workflow: capture a snapshot first to obtain refs, then use those refs with tools like browser_click or browser_type. This is strong implicit guidance, though it lacks an explicit 'when not to use' or a direct comparison to alternatives.

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