nex_browser_evaluate

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

With no annotations present, the description carries the full burden. It discloses that permission must be enabled, but does not mention whether evaluation can mutate page state, what the return value looks like, or what happens if permission is missing.

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?

A single sentence with no filler. The permission qualifier adds relevant context and the statement is appropriately front-loaded and efficient.

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?

For a tool that executes arbitrary JavaScript, the description is under-specified: it omits return behavior, side effects, and relationship to the similar run_code tool. The existing schema and absence of output schema leave too many unanswered questions for reliable 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 schema describes pageId and sessionId, but the required expression parameter has no description, and the tool description does not clarify its syntax or role beyond 'Evaluate JavaScript.' The minimal description adds little meaning beyond the schema fields.

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 identifies the action as evaluating JavaScript and notes a permission prerequisite. However, it does not specify that evaluation occurs in the browser page or distinguish this from the sibling nex_browser_run_code, which likely performs a similar action.

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 phrase 'when the dedicated evaluate permission is enabled' gives a precondition but offers no guidance on when to prefer this tool over nex_browser_run_code or when not to use it. No alternatives or contextual triggers are provided.

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