browser_execute

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

The description prominently warns 'Danger tier: the script runs with the page's own privileges, the same reach as shell access to the browser profile', which is a strong behavioral disclosure. It also mentions the JSON envelope return. However, it doesn't discuss other potential side effects (e.g., page state changes, blocking), though the danger warning largely covers this.

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 well-structured with a danger warning first, then Args and Returns sections. Every sentence serves a purpose, and it is concise with no filler.

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 an output schema, so return values need not be detailed; the description mentions the JSON envelope. It covers both parameters, the danger level, and the source of serialno. It lacks explicit usage context (covered under usage_guidelines), but for a simple JS evaluation tool it is adequately complete.

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 0%, so the description fully compensates by explaining both parameters: serialno ('from list_devices') and script ('JavaScript source to evaluate'). This adds clear meaning beyond the bare schema.

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 'Evaluate JavaScript in the page' with a specific verb and resource. This is unique among siblings, as no other tool offers arbitrary JS execution, so it is easily distinguished.

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?

No explicit guidance on when to use this tool versus other browser actions. It implies use for custom JS but doesn't mention alternatives or exclusions, leaving the agent to infer from the name and siblings.

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