browser_evaluate

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

The annotations mark destructiveHint=true and openWorldHint=true, indicating potential side effects and broad impact, but the description does not elaborate on these behaviors. It fails to warn that executing arbitrary JavaScript may modify page state, trigger network requests, or cause other unintended consequences. The description adds minimal transparency beyond the annotations.

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 sentence, concise and front-loaded. It contains no unnecessary words. However, its brevity sacrifices critical information, resulting in under-specification. Still, it is well-structured for its length.

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 (JavaScript execution, destructive potential, multiple sibling tools), the description is severely incomplete. It does not explain the difference from browser_run_code_unsafe, the role of element vs target, how permissions work, what the return value looks like, or the implications of the destructiveHint and openWorldHint annotations. The minimal description leaves the agent underinformed.

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 100%, so the input schema already documents each parameter adequately. The tool description does not add any extra meaning, such as explaining the relationship between 'target' and 'element' or when to use 'filename'. With baseline coverage, a score of 3 is appropriate as the description neither harms nor significantly helps.

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 evaluates JavaScript expressions on a page or element, specifying the verb 'evaluate' and the resource 'JavaScript expression'. However, it does not differentiate from the sibling tool 'browser_run_code_unsafe', which also likely runs JavaScript, leaving ambiguity about when to use each.

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 like browser_run_code_unsafe, nor does it mention preconditions, permissions, or when not to use it. The agent is left without context for selection.

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