agent_browser_run

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

With no annotations, the description carries the burden of behavioral disclosure. It adds key context: the tool is low-level, deterministic, and shares the browser session with Stagehand. However, it does not mention risks such as side effects on the browser state or that arbitrary commands could be destructive, which prevents a perfect score.

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 tightly written sentences. The action is front-loaded, and every sentence adds value: purpose, usage guidance, and session-sharing context. 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?

For a simple one-parameter command runner, the description provides strong context: what it does, when to prefer it, and its relationship to Stagehand. It lacks explicit return/output or error behavior, but the presence of sibling agent_browser_help and the schema's examples mitigate this gap.

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 only parameter, 'args', has 100% schema description coverage with examples. The description doesn't add parameter-level details beyond the schema, so the baseline score of 3 is appropriate.

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 opens with a specific verb and resource ('Run a low-level browser command') and immediately differentiates from Stagehand by emphasizing 'precise, deterministic control'. It lists concrete use cases (element-by-ref interactions, DOM inspection, network debugging, JS evaluation), making the tool's scope clear.

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?

Explicitly states when to use this tool over alternatives: 'Use over Stagehand when you need precise, deterministic control'. Also notes it shares the same browser session as Stagehand, implicitly warning against creating a separate session.

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