browser_evaluate

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

Annotations already indicate destructiveHint=true and openWorldHint=true, so the description need not repeat those. However, it adds no extra behavioral context—such as the scope of execution, potential side effects on page state, or security implications—beyond stating 'on page or element'. The description simply restates the action without revealing operational boundaries.

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 a single concise sentence with no superfluous words. It efficiently conveys the core action, though it sacrifices depth for brevity. Front-loaded with the action, but could be more informative in the same space.

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 four parameters, no output schema, and annotations that suggest destructiveness, the description is incomplete. It does not explain what happens when no target or element is provided, how the function parameter is structured beyond the inline comment, or what the return format is (text vs. file). A richer description is needed for correct invocation.

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 provides full (100%) coverage with clear parameter descriptions. The tool description adds little beyond the schema, merely hinting at the function parameter format. Since schema coverage is high, a baseline of 3 is appropriate; the description does not enhance understanding of the target/element distinction or filename behavior.

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 verb 'Evaluate' and the resource 'JavaScript expression on page or element', which distinguishes it from tools like browser_navigate or browser_click. However, it does not explicitly differentiate from the sibling tool browser_run_code_unsafe, which also executes JavaScript, limiting clarity in choice.

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 such as browser_run_code_unsafe, browser_type, or browser_fill_form. There is no mention of prerequisites, limitations, or the recommended use cases, leaving the agent without decision support.

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