Act on page element

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does reveal that clicks run a full CDP mouse sequence and that press supports navigation keystrokes, but it omits important behaviors such as the 'confirmed' parameter's role in potentially submitting clicks or the fallback 'selector' behavior, leaving gaps in transparency.

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 three sentences, each contributing distinct information: purpose, usage preference, and action-specific behavior. It is front-loaded with the main purpose and contains no redundant or filler content.

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 complexity (8 parameters, no annotations, no output schema), the description covers the main actions but omits critical context around the 'confirmed' parameter for potentially submitting clicks and the 'selector' fallback for scenarios without a snapshot ref. These gaps prevent the description from being fully complete for safe and correct usage.

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 75%, so the schema already documents most parameters. The description adds semantic value beyond the schema by explaining what each 'kind' value does (click, fill, press, select) and emphasizing preferring 'ref' over 'selector'. This helps the agent understand the purpose of the kind enum, which lacks a schema description.

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 tool performs 'one atomic high-level action' and enumerates the action kinds (click, fill, press, select), providing a specific verb and resource. However, it does not explicitly distinguish itself from sibling tools like browser_click or browser_fill, so it lacks differentiation.

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 offers usage guidance such as 'Prefer a ref from the latest browser_snapshot' and clarifies that press supports navigation keys and select is for native controls. Yet it does not explicitly state when to use this tool versus alternatives like browser_click or browser_fill, leaving the usage context implied rather than explicit.

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